diff --git a/.gitignore b/.gitignore
index d37dbd606..49c7a1e7f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,6 +17,6 @@ manifests/storage/*
 roles/cluster-backup/files/*
 !roles/cluster-backup/files/readme.md
 
-# roles/xxx/vars, exclude roles/os-harden/vars/
+# role based variable settings, exclude roles/os-harden/vars/
 /roles/*/vars/*
 !/roles/os-harden/vars/
diff --git a/01.prepare.yml b/01.prepare.yml
index 0663f716f..fd1bcefa5 100644
--- a/01.prepare.yml
+++ b/01.prepare.yml
@@ -1,14 +1,14 @@
-# 集群内时间同步
+# [optional] to synchronize time of nodes with 'chrony' 
 - hosts: all
   roles:
   - { role: chrony, when: "hostvars[groups.deploy[0]]['NTP_ENABLED'] == 'yes'" }
 
-# 在deploy节点生成CA相关证书
+# to create CA, kubeconfig, kube-proxy.kubeconfig etc. on 'deploy' node
 - hosts: deploy
   roles:
   - deploy
 
-# 集群节点的公共配置任务
+# prepare tasks for all nodes
 - hosts:
   - kube-master
   - kube-node
@@ -18,7 +18,7 @@
   roles:
   - prepare
 
-# [可选]多master部署时的负载均衡配置
+#  [optional] to install loadbalance service, only needed by multi-master cluster 
 - hosts: lb
   roles:
   - lb
diff --git a/02.etcd.yml b/02.etcd.yml
index b130fb9b0..34a5941df 100644
--- a/02.etcd.yml
+++ b/02.etcd.yml
@@ -1,3 +1,4 @@
+# to install etcd cluster
 - hosts: etcd
   roles:
   - etcd
diff --git a/03.docker.yml b/03.docker.yml
index 8f3eb975c..02f3a7ebd 100644
--- a/03.docker.yml
+++ b/03.docker.yml
@@ -1,3 +1,4 @@
+# to install docker service
 - hosts:
   - kube-master
   - kube-node
diff --git a/04.kube-master.yml b/04.kube-master.yml
index def90cb85..232ecfe21 100644
--- a/04.kube-master.yml
+++ b/04.kube-master.yml
@@ -1,16 +1,16 @@
+# to set up 'kube-master' nodes
 - hosts: kube-master
   roles:
   - kube-master
   - kube-node
-  # 禁止业务 pod调度到 master节点
   tasks:
-  - name: 禁止业务 pod调度到 master节点
+  - name: Making master nodes SchedulingDisabled
     shell: "{{ bin_dir }}/kubectl cordon {{ inventory_hostname }} "
     delegate_to: "{{ groups.deploy[0] }}"
     when: DEPLOY_MODE != "allinone"
     ignore_errors: true
 
-  - name: 设置master节点role
+  - name: Setting master role name 
     shell: "{{ bin_dir }}/kubectl label node {{ inventory_hostname }} kubernetes.io/role=master --overwrite"
     ignore_errors: true
     delegate_to: "{{ groups.deploy[0] }}"
diff --git a/05.kube-node.yml b/05.kube-node.yml
index f8cccdcec..5c7ddd3d0 100644
--- a/05.kube-node.yml
+++ b/05.kube-node.yml
@@ -1,3 +1,4 @@
+# to set up 'kube-node' nodes
 - hosts: kube-node
   roles:
   - kube-node
diff --git a/06.network.yml b/06.network.yml
index 00569e66c..f683c36b5 100644
--- a/06.network.yml
+++ b/06.network.yml
@@ -1,4 +1,4 @@
-# 集群网络插件部署，只能选择一种安装
+# to install network plugin, only one can be choosen 
 - hosts:
   - kube-master
   - kube-node
diff --git a/07.cluster-addon.yml b/07.cluster-addon.yml
index f9fabcc76..efe756f68 100644
--- a/07.cluster-addon.yml
+++ b/07.cluster-addon.yml
@@ -1,3 +1,4 @@
+# to install clust-addons
 - hosts:
   - kube-node 
   roles:
diff --git a/11.harbor.yml b/11.harbor.yml
index afbcb0790..1172f7330 100644
--- a/11.harbor.yml
+++ b/11.harbor.yml
@@ -1,3 +1,6 @@
+# [optional] to set up a HARBOR, and to integrate the HARBOR with k8s cluster
+# read the guide: 'guide/harbor.md'
+
 - hosts: harbor
   roles:
   - { role: chrony, when: "hostvars[groups.deploy[0]]['NTP_ENABLED'] == 'yes' and NEW_INSTALL == 'yes'" }
@@ -5,7 +8,7 @@
   - { role: docker, when: "NEW_INSTALL == 'yes'" }
   - { role: harbor, when: "NEW_INSTALL == 'yes'" }
   tasks:
-  - name: 获取harbor服务器证书
+  - name: Fetching the HARBOR SERVER's CA cert
     fetch:
       src: "{{ ca_dir }}/ca.pem"
       dest: "{{ base_dir }}/down/"
@@ -19,14 +22,14 @@
   vars:
     harbor_domain: "{{ hostvars[groups.harbor[0]]['HARBOR_DOMAIN'] }}"
   tasks:
-  - name: harbor证书目录创建
+  - name: Creating cert dir of the HARBOR SERVER for the docker daemon
     file: name=/etc/docker/certs.d/{{ harbor_domain }} state=directory
   
-  - name: 推送harbor服务器证书
+  - name: Installing the HARBOR SERVER's cert on k8s nodes
     copy: src={{ base_dir }}/down/ca.pem dest=/etc/docker/certs.d/{{ harbor_domain }}/ca.crt
 
-  # 如果你的环境中有dns服务器，可以跳过hosts文件设置
-  - name: 增加harbor的hosts解析
+  # [optional] if you have a DNS server, add an 'A record' instead
+  - name: Adding an '/etc/hosts' entry for the HARBOR DOMAIN
     lineinfile:
       dest: /etc/hosts
       state: present
diff --git a/20.addnode.yml b/20.addnode.yml
index 27e1eaffd..99d5f8db3 100644
--- a/20.addnode.yml
+++ b/20.addnode.yml
@@ -4,7 +4,7 @@
   - prepare
   - docker
   - kube-node
-  # 根据hosts中配置，以下两种网络只会安装一种
+  # 
   - { role: calico, when: "CLUSTER_NETWORK == 'calico'" }
   - { role: cilium, when: "CLUSTER_NETWORK == 'cilium'" }
   - { role: flannel, when: "CLUSTER_NETWORK == 'flannel'" }
diff --git a/21.addmaster.yml b/21.addmaster.yml
index 4c54ca498..097efcd39 100644
--- a/21.addmaster.yml
+++ b/21.addmaster.yml
@@ -1,4 +1,4 @@
-# 重新配置启动 haproxy
+# reconfigure and restart the haproxy service
 - hosts: lb
   roles:
   - lb
@@ -10,20 +10,20 @@
   - docker
   - kube-master
   - kube-node
-  # 根据hosts中配置，以下两种网络只会安装一种
+  #
   - { role: calico, when: "CLUSTER_NETWORK == 'calico'" }
   - { role: cilium, when: "CLUSTER_NETWORK == 'cilium'" }
   - { role: flannel, when: "CLUSTER_NETWORK == 'flannel'" }
   - { role: kube-router, when: "CLUSTER_NETWORK == 'kube-router'" }
-  # 禁止业务 pod调度到 master节点
+  # 
   tasks:
-  - name: 禁止业务 pod调度到 master节点
+  - name: Making master nodes SchedulingDisabled
     shell: "{{ bin_dir }}/kubectl cordon {{ inventory_hostname }} "
     delegate_to: "{{ groups.deploy[0] }}"
     when: DEPLOY_MODE != "allinone"
     ignore_errors: true
 
-  - name: 设置master节点role
+  - name: Setting master role name
     shell: "{{ bin_dir }}/kubectl label node {{ inventory_hostname }} kubernetes.io/role=master --overwrite"
     ignore_errors: true
     delegate_to: "{{ groups.deploy[0] }}"
diff --git a/22.upgrade.yml b/22.upgrade.yml
index 73552da35..e27866829 100644
--- a/22.upgrade.yml
+++ b/22.upgrade.yml
@@ -1,7 +1,7 @@
-# 集群更新存在一定风险，请谨慎操作
-# 使用命令：ansible-playbook -t upgrade_k8s 22.upgrade.yml
+# WARNING: Upgrade the k8s cluster can be risky. Make sure you know what you are doing.
+# Read the guide: 'op/upgrade.md' .
 
-# 更新kubectl二进制
+# update kubectl binary
 - hosts:
   - kube-master
   - kube-node
@@ -9,12 +9,12 @@
   roles:
   - prepare
 
-# 更新etcd集群
+# update etcd 
 - hosts: etcd
   roles:
   - etcd
 
-# docker更新，为保证不中断业务，不自动重启docker服务
+# update docker binary
 - hosts:
   - kube-master
   - new-master
@@ -23,7 +23,7 @@
   roles:
   - docker
 
-# 更新master节点
+# update masters
 - hosts: 
   - kube-master
   - new-master
@@ -31,7 +31,7 @@
   - kube-master
   - kube-node
 
-# 更新node节点
+# update nodes
 - hosts: 
   - kube-node
   - new-node
diff --git a/23.backup.yml b/23.backup.yml
index 09b9270d6..3abad1067 100644
--- a/23.backup.yml
+++ b/23.backup.yml
@@ -1,4 +1,5 @@
-# 集群备份脚本，请详细参阅文档 docs/op/cluster_restore.md 
+# cluster-backup playbook
+# read the guide: 'op/cluster_restore.md'
 
 - hosts:
   - etcd
@@ -8,14 +9,14 @@
 - hosts:
   - deploy
   tasks:
-  - name: 准备备份目录
+  - name: Creating backup dirs
     file: name={{ item }} state=directory
     with_items:
     - "{{ base_dir }}/roles/cluster-backup/files/ca"    
     - "{{ base_dir }}/roles/cluster-backup/files/hosts"   
     - "{{ base_dir }}/roles/cluster-backup/files/snapshot"   
 
-  - name: 备份 CA 相关文件
+  - name: Backing up CA sth
     copy:
       src: "{{ ca_dir }}/{{ item }}"
       dest: "{{ base_dir }}/roles/cluster-backup/files/ca/{{ item }}"
@@ -26,25 +27,25 @@
     - ca-csr.json
     - ca-config.json
 
-  - name: 备份 ansible hosts 1
+  - name: Backing up ansible hosts-1
     copy:
       src: "{{ base_dir }}/hosts"
       dest: "{{ base_dir }}/roles/cluster-backup/files/hosts/hosts"
     register: p
 
-  - name: 备份 ansible hosts 2
+  - name: Backing up ansible hosts-2
     shell: "cd {{ base_dir }}/roles/cluster-backup/files/hosts && \
 	cp -fp hosts hosts-$(date +'%Y%m%d%H%M')"
-    when: p | changed
+    when: 'p is changed'
 
-  - name: 备份 etcd snapshot 1
+  - name: Backing up etcd snapshot-1
     copy:
       src: "{{ base_dir }}/roles/cluster-backup/files/snapshot.db"
       dest: "{{ base_dir }}/roles/cluster-backup/files/snapshot/snapshot.db"
     register: q
 
-  - name: 备份 etcd snapshot 2
+  - name: Backing up etcd snapshot-2
     shell: "cd {{ base_dir }}/roles/cluster-backup/files/ && \
 	mv -f snapshot.db snapshot/snapshot-$(date +'%Y%m%d%H%M').db"
-    when: q | changed
+    when: 'q is changed'
 
diff --git a/24.restore.yml b/24.restore.yml
index c5189026b..d9c90e2f8 100644
--- a/24.restore.yml
+++ b/24.restore.yml
@@ -1,12 +1,13 @@
-# 集群从备份恢复的脚本，使用请参阅文档 docs/op/cluster_restore.md
+# cluster-restore playbook
+# read the guide: 'op/cluster_restore.md'
 
-# 在deploy节点恢复CA相关证书
+# to restore CA sth on 'deploy' node
 - hosts: deploy
   tasks: 
-  - name: 恢复CA 文件夹
+  - name: Restoring dirs of CA sth
     file: name=/etc/kubernetes/ssl/ state=directory
 
-  - name: 恢复CA 相关文件
+  - name: Restoring CA sth
     copy: 
       src: "{{ base_dir }}/roles/cluster-backup/files/ca/{{ item }}"
       dest: "{{ ca_dir }}/{{ item }}"
@@ -21,22 +22,22 @@
   roles:
   - deploy
 
-# 集群节点的公共配置任务
+# pre-tasks on all nodes
 - hosts: all
   roles:
   - prepare
 
-# [可选]多master部署时的负载均衡配置
+# [optional] only needed by multi-master cluster
 - hosts: lb
   roles:
   - lb
 
-# 创建etcd集群
+# to install etcd cluster
 - hosts: etcd
   roles:
   - etcd
 
-# docker服务安装
+# to install docker
 - hosts:
   - kube-master
   - kube-node
@@ -45,31 +46,32 @@
   roles:
   - docker
 
+# to set up 'kube-master' nodes
 - hosts:
   - kube-master
   - new-master
   roles:
   - kube-master
   - kube-node
-  # 禁止业务 pod调度到 master节点
+  # 
   tasks:
-  - name: 禁止业务 pod调度到 master节点
+  - name: Making master nodes SchedulingDisabled
     shell: "{{ bin_dir }}/kubectl cordon {{ inventory_hostname }} "
     when: DEPLOY_MODE != "allinone"
     ignore_errors: true
 
-  - name: 设置master节点role
+  - name: Setting master role name
     shell: "{{ bin_dir }}/kubectl label node {{ inventory_hostname }} kubernetes.io/role=master --overwrite"
     ignore_errors: true
 
-# node 节点部署
+# to set up 'kube-node' nodes
 - hosts:
   - kube-node
   - new-node
   roles:
   - kube-node
 
-# etcd 集群进行数据恢复
+# to restore data of etcd cluster
 - hosts: etcd
   roles:
   - cluster-restore
diff --git a/90.setup.yml b/90.setup.yml
index 8a4bb1501..c9e28cb01 100644
--- a/90.setup.yml
+++ b/90.setup.yml
@@ -1,14 +1,14 @@
-# 集群内时间同步
+# [optional] to synchronize time of nodes with 'chrony'
 - hosts: all
   roles:
   - { role: chrony, when: "hostvars[groups.deploy[0]]['NTP_ENABLED'] == 'yes'" }
 
-# 在deploy节点生成CA相关证书，以供整个集群使用
+# to create CA, kubeconfig, kube-proxy.kubeconfig etc. on 'deploy' node
 - hosts: deploy
   roles:
   - deploy
 
-# 集群节点的公共配置任务
+# prepare tasks for all nodes
 - hosts:
   - kube-master
   - kube-node
@@ -18,46 +18,47 @@
   roles:
   - prepare
 
-# [可选]多master部署时的负载均衡配置
+# [optional] to install loadbalance service, only needed by multi-master cluster
 - hosts: lb
   roles:
   - lb
 
-# 创建etcd集群
+# to install etcd cluster
 - hosts: etcd
   roles:
   - etcd
 
-# docker服务安装
+# to install docker service
 - hosts:
   - kube-master
   - kube-node
   roles:
   - docker
 
+# to set up 'kube-master' nodes
 - hosts: kube-master
   roles:
   - kube-master
   - kube-node
-  # 禁止业务 pod调度到 master节点
+  # 
   tasks:
-  - name: 禁止业务 pod调度到 master节点
+  - name: Making master nodes SchedulingDisabled
     shell: "{{ bin_dir }}/kubectl cordon {{ inventory_hostname }} "
     delegate_to: "{{ groups.deploy[0] }}"
     when: DEPLOY_MODE != "allinone"
     ignore_errors: true
 
-  - name: 设置master节点role
+  - name: Setting master role name
     shell: "{{ bin_dir }}/kubectl label node {{ inventory_hostname }} kubernetes.io/role=master --overwrite"
     ignore_errors: true
     delegate_to: "{{ groups.deploy[0] }}"
 
-# node 节点部署
+# to set up 'kube-node' nodes
 - hosts: kube-node
   roles:
   - { role: kube-node, when: "DEPLOY_MODE != 'allinone'" }
 
-# 集群网络插件部署，只能选择一种安装
+# to install network plugin, only one can be choosen
 - hosts:
   - kube-master
   - kube-node
@@ -67,7 +68,7 @@
   - { role: flannel, when: "CLUSTER_NETWORK == 'flannel'" }
   - { role: kube-router, when: "CLUSTER_NETWORK == 'kube-router'" }
 
-# 集群插件安装
+# to install clust-addons
 - hosts:
   - kube-node
   roles:
diff --git a/99.clean.yml b/99.clean.yml
index aa10c437d..e72614f5a 100644
--- a/99.clean.yml
+++ b/99.clean.yml
@@ -1,7 +1,7 @@
-# 警告：此脚本将清理整个K8S集群，包括所有POD、ETCD数据等
-# 请三思后运行此脚本 ansible-playbook 99.clean.yml
+# WARNING: This playbook will erase the entire k8s-cluster, include PODs, ETCD data etc.
+# Make sure you know what you are doing.
 
-# 清理 kube-node 相关服务
+# to clean 'kube-node' nodes
 - hosts:
   - kube-master
   - new-master
@@ -15,11 +15,11 @@
     - kube-proxy
     ignore_errors: true
 
-  - name: umount kubelet 挂载的目录
+  - name: umount kubelet filesystems
     shell: "mount | grep '/var/lib/kubelet'| awk '{print $3}'|xargs umount"
     ignore_errors: true
 
-  - name: 清理目录和文件
+  - name: remove files and dirs of 'kube-node' nodes
     file: name={{ item }} state=absent
     with_items:
     - "/var/lib/kubelet/"
@@ -28,7 +28,7 @@
     - "/etc/systemd/system/kube-proxy.service"
     - "/opt/kube/kube-system/"
 
-# 清理 kube-master 相关
+# to clean 'kube-master' nodes
 - hosts:
   - kube-master
   - new-master
@@ -41,7 +41,7 @@
     - kube-scheduler
     ignore_errors: true
 
-  - name: 清理目录和文件
+  - name: remove files and dirs of 'kube-master' nodes
     file: name={{ item }} state=absent
     with_items:
     - "/var/run/kubernetes"
@@ -49,14 +49,14 @@
     - "/etc/systemd/system/kube-controller-manager.service"
     - "/etc/systemd/system/kube-scheduler.service"
 
-# 清理集群docker服务、网络相关
+# to clean docker service and networking
 - hosts:
   - kube-master
   - new-master
   - kube-node
   - new-node
   tasks:
-  - name: 清理kube-router相关
+  - name: clean 'kube-router' stuff
     shell: "{{ bin_dir }}/docker run --privileged --net=host cloudnativelabs/kube-router --cleanup-config"
     ignore_errors: true
     when: "CLUSTER_NETWORK == 'kube-router'"
@@ -68,15 +68,14 @@
       enabled: no
     ignore_errors: true
 
-  # 因为calico-kube-controller使用了host网络，相当于使用了docker -net=host，需要
-  # 卸载 /var/run/docker/netns/default
-  - name: 卸载docker 相关fs1
+  # as k8s-network-plugins use host-network, '/var/run/docker/netns/default' must be umounted
+  - name: unmount docker filesystem-1
     mount: path=/var/run/docker/netns/default state=unmounted
 
-  - name: 卸载docker 相关fs2
+  - name: unmount docker filesystem-2
     mount: path=/var/lib/docker/overlay state=unmounted
 
-  - name: 清理目录和文件
+  - name: remove files and dirs
     file: name={{ item }} state=absent
     with_items:
     - "/etc/cni/"
@@ -100,13 +99,13 @@
     - "/etc/bash_completion.d/docker"
     ignore_errors: true
 
-  - name: 清理 iptables
+  - name: cleanup iptables
     shell: "iptables -F && iptables -X \
 	&& iptables -F -t nat && iptables -X -t nat \
 	&& iptables -F -t raw && iptables -X -t raw \
 	&& iptables -F -t mangle && iptables -X -t mangle"
 
-  - name: 清理网络
+  - name: cleanup networks
     shell: "ip link del docker0; \
 	ip link del tunl0; \
 	ip link del flannel.1; \
@@ -121,12 +120,12 @@
 	systemctl restart network"
     ignore_errors: true
 
-  - name: 清理calico残留路由
+  - name: cleanup 'calico' routes
     shell: "for rt in `ip route|grep bird|sed 's/blackhole//'|awk '{print $1}'`;do ip route del $rt;done;"
     when: "CLUSTER_NETWORK == 'calico'"
     ignore_errors: true
 
-# 清理etcd 集群相关
+# to clean 'etcd' nodes
 - hosts: etcd
   tasks:
   - name: stop and disable etcd service
@@ -136,7 +135,7 @@
       enabled: no
     ignore_errors: true
 
-  - name: 清理目录和文件
+  - name: remove files and dirs
     file: name={{ item }} state=absent
     with_items:
     - "/var/lib/etcd"
@@ -144,7 +143,7 @@
     - "/backup/k8s"
     - "/etc/systemd/system/etcd.service"
 
-# 清理负载均衡相关
+# to clean 'lb' nodes
 - hosts: lb
   tasks:
   - name: stop keepalived service
@@ -155,12 +154,13 @@
     shell: systemctl disable haproxy && systemctl stop haproxy
     ignore_errors: true
 
-  - name: 清理LB 配置文件目录
+  - name: remove files and dirs
     file: name={{ item }} state=absent
     with_items:
     - "/etc/haproxy"
     - "/etc/keepalived"
 
+# to clean ntp, certs and keys, env path
 - hosts:
   - kube-master
   - new-master
@@ -178,7 +178,7 @@
     ignore_errors: true
     tags: rm_ntp 
 
-  - name: 清理证书目录和文件
+  - name: clean certs and keys
     file: name={{ item }} state=absent
     with_items:
     - "/etc/kubernetes/"
@@ -186,7 +186,7 @@
     - "/root/.kube/"
     - "/etc/docker/"
 
-  - name: 清理自动生成的PATH
+  - name: clean 'ENV PATH'
     lineinfile:
       dest: ~/.bashrc
       state: absent
diff --git a/bin/readme.md b/bin/readme.md
index 1901367af..0cd1fcc06 100644
--- a/bin/readme.md
+++ b/bin/readme.md
@@ -1,3 +1,3 @@
-# 项目二进制目录
+# Binaries for installing k8s 
 
-集群用到的所有二进制文件已打包好供下载 https://pan.baidu.com/s/1c4RFaA
+Binaries can be downloaded at https://pan.baidu.com/s/1c4RFaA, alternatively they can be downloaded from official github repos separately.
diff --git a/docs/guide/ipvs.md b/docs/guide/ipvs.md
index e25f9bc7e..882a24dbd 100644
--- a/docs/guide/ipvs.md
+++ b/docs/guide/ipvs.md
@@ -15,7 +15,7 @@ After=network.target
 
 [Service]
 WorkingDirectory=/var/lib/kube-proxy
-ExecStart=/opt/kube/bin/kube-proxy \
+ExecStart={{ bin_dir }}/kube-proxy \
   --bind-address={{ NODE_IP }} \
   --hostname-override={{ NODE_IP }} \
   --kubeconfig=/etc/kubernetes/kube-proxy.kubeconfig \
diff --git a/down/download.sh b/down/download.sh
index 41b3f724d..15530808b 100644
--- a/down/download.sh
+++ b/down/download.sh
@@ -1,16 +1,17 @@
 #!/bin/bash
-#主要组件版本如下
-export K8S_VER=v1.10.2
-export ETCD_VER=v3.3.8
-export DOCKER_VER=17.03.2-ce
-export CNI_VER=v0.7.0
-export DOCKER_COMPOSE=1.18.0
-export HARBOR=v1.2.2
+# This script describes where to download the official released binaries needed 
+# It's suggested to download the entire *.tar.gz at https://pan.baidu.com/s/1c4RFaA
 
-echo "\n建议直接下载本人打包好的所有必要二进制包k8s-***.all.tar.gz，然后解压到bin目录"
-echo "\n建议不使用此脚本，如果你想升级组件或者实验，请通读该脚本，必要时适当修改后使用"
-echo "\n注意1：请按照以下链接手动下载二进制包到down目录中"
-echo "\n注意2：如果还没有手工下载tar包，请Ctrl-c结束此脚本"
+# example releases
+K8S_VER=v1.10.4
+ETCD_VER=v3.3.8
+DOCKER_VER=17.03.2-ce
+CNI_VER=v0.6.0
+DOCKER_COMPOSE=1.18.0
+HARBOR=v1.5.2
+
+echo "\nNote1: Before this script, please finish downloading binaries manually from following urls."
+echo "\nNote2：If binaries are not ready, use `Ctrl + C` to stop this script."
 
 echo "\n----download k8s binary at:"
 echo https://dl.k8s.io/${K8S_VER}/kubernetes-server-linux-amd64.tar.gz
@@ -38,36 +39,34 @@ echo https://github.com/containernetworking/plugins/releases
 
 sleep 30
 
-### 准备证书工具程序
-echo "\n准备证书工具程序..."
+### prepare 'cfssl' cert tool suit
+echo "\nMoving 'cfssl' to 'bin' dir..."
 if [ -f "cfssl_linux-amd64" ]; then
   mv -f cfssl_linux-amd64 ../bin/cfssl
 else
-  echo 请先下载https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
+  echo Please download 'cfssl' at 'https://pkg.cfssl.org/R1.2/cfssl_linux-amd64'
 fi
 if [ -f "cfssljson_linux-amd64" ]; then
   mv -f cfssljson_linux-amd64 ../bin/cfssljson
 else
-  echo 请先下载https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
+  echo Please download 'cfssljson' at 'https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64'
 fi
 if [ -f "cfssl-certinfo_linux-amd64" ]; then
   mv -f cfssl-certinfo_linux-amd64 ../bin/cfssl-certinfo
 else
-  echo 请先下载https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
+  echo Please download 'cfssl-certinfo' at 'https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64'
 fi
 
-### 准备etcd程序
-echo "\n准备etcd二进制程序..."
+### prepare 'etcd' binaries
 if [ -f "etcd-${ETCD_VER}-linux-amd64.tar.gz" ]; then
   echo "\nextracting etcd binaries..."
   tar zxf etcd-${ETCD_VER}-linux-amd64.tar.gz
   mv -f etcd-${ETCD_VER}-linux-amd64/etcd* ../bin
 else
-  echo 请先下载etcd-${ETCD_VER}-linux-amd64.tar.gz
+  echo Please download 'etcd-${ETCD_VER}-linux-amd64.tar.gz' first
 fi
 
-### 准备kubernetes程序
-echo "\n准备kubernetes二进制程序..."
+### prepare kubernetes binaries
 if [ -f "kubernetes-server-linux-amd64.tar.gz" ]; then
   echo "\nextracting kubernetes binaries..."
   tar zxf kubernetes-server-linux-amd64.tar.gz
@@ -78,11 +77,10 @@ if [ -f "kubernetes-server-linux-amd64.tar.gz" ]; then
   mv -f kubernetes/server/bin/kube-proxy ../bin
   mv -f kubernetes/server/bin/kube-scheduler ../bin
 else
-  echo 请先下载kubernetes-server-linux-amd64.tar.gz
+  echo Please download 'kubernetes-server-linux-amd64.tar.gz' first
 fi
 
-### 准备docker程序
-echo "\n准备docker二进制程序..."
+### prepare docker binaries
 if [ -f "docker-${DOCKER_VER}.tgz" ]; then
   echo "\nextracting docker binaries..."
   tar zxf docker-${DOCKER_VER}.tgz
@@ -91,11 +89,10 @@ if [ -f "docker-${DOCKER_VER}.tgz" ]; then
     mv -f docker/completion/bash/docker ../roles/docker/files/docker
   fi
 else
-  echo 请先下载docker-${DOCKER_VER}.tgz
+  echo Please download 'docker-${DOCKER_VER}.tgz' first 
 fi
 
-### 准备cni plugins，仅安装flannel需要，安装calico由容器专门下载cni plugins 
-echo "\n准备cni plugins，仅安装flannel需要，安装calico由容器专门下载cni plugins..."
+### prepare cni plugins, needed by flannel;
 if [ -f "cni-${CNI_VER}.tgz" ]; then
   echo "\nextracting cni plugins binaries..."
   tar zxf cni-${CNI_VER}.tgz
@@ -105,5 +102,5 @@ if [ -f "cni-${CNI_VER}.tgz" ]; then
   mv -f loopback ../bin
   mv -f portmap ../bin
 else
-  echo 请先下载cni-${CNI_VER}.tgz
+  echo Please download 'cni-${CNI_VER}.tgz' first 
 fi
diff --git a/down/offline_images b/down/offline_images
index 3231639d2..664b68dfb 100644
--- a/down/offline_images
+++ b/down/offline_images
@@ -1,42 +1,42 @@
 ###---[basic_images ]
-# dns-addon 插件
+# dns-addon 
 coredns/coredns:1.1.3
 mirrorgooglecontainers/k8s-dns-kube-dns-amd64:1.14.10
 mirrorgooglecontainers/k8s-dns-dnsmasq-nanny-amd64:1.14.10
 mirrorgooglecontainers/k8s-dns-sidecar-amd64:1.14.10
-# metrics-server 插件
+# metrics-server 
 mirrorgooglecontainers/metrics-server-amd64:v0.2.1
-# calico 网络插件
+# calico 
 calico/node:v3.1.3
 calico/cni:v3.1.3
 calico/kube-controllers:v3.1.3
-# cilium 网络插件
+# cilium 
 cilium/cilium:v1.1.2
-# flannel 网络插件
+# flannel 
 jmgao1983/flannel:v0.10.0-amd64
-# kube-router 网络插件
+# kube-router 
 cloudnativelabs/kube-router:v0.2.0-beta.9
-# dashboard 插件
+# dashboard 
 mirrorgooglecontainers/kubernetes-dashboard-amd64:v1.8.3
-# pause 基础容器镜像
+# pause 
 mirrorgooglecontainers/pause-amd64:3.1
 busybox:1.28.4
-# traefik ingress 镜像
+# traefik ingress 
 traefik:v1.6
-# heapster 插件
+# heapster 
 mirrorgooglecontainers/heapster-grafana-amd64:v4.4.3
 mirrorgooglecontainers/heapster-amd64:v1.5.1
 mirrorgooglecontainers/heapster-influxdb-amd64:v1.3.3
 
 ###---[extra-images]
-# helm 服务端
+# helm tiller server 
 jmgao1983/tiller:v2.9.1
-# efk 插件
+# efk 
 mirrorgooglecontainers/elasticsearch:v5.6.4
 alpine:3.6
 mirrorgooglecontainers/fluentd-elasticsearch:v2.0.2
 jmgao1983/kibana:5.6.4
-# nfs 动态PV
+# nfs dynamic PV provisioner
 jmgao1983/nfs-client-provisioner:latest
 # prometheus
 busybox:latest
diff --git a/example/hosts.allinone.example b/example/hosts.allinone.example
index 6ed941d6d..63cbf1276 100644
--- a/example/hosts.allinone.example
+++ b/example/hosts.allinone.example
@@ -1,9 +1,10 @@
-# 集群部署节点：一般为运行ansible 脚本的节点
-# 变量 NTP_ENABLED (=yes/no) 设置集群是否安装 chrony 时间同步
+# 'deploy' node, which the ansible-playbooks usually run on
+# variable 'NTP_ENABLED(=yes/no)' enables/disables the NTP server 'chrony'
 [deploy]
 192.168.1.1 NTP_ENABLED=no
 
-# etcd集群请提供如下NODE_NAME，注意etcd集群必须是1,3,5,7...奇数个节点
+# 'etcd' cluster must have odd member(s) (1,3,5,...)
+# variable 'NODE_NAME' is the distinct name of a member in 'etcd' cluster
 [etcd]
 192.168.1.1 NODE_NAME=etcd1
 
@@ -13,57 +14,57 @@
 [kube-node]
 192.168.1.1
 
-# 参数 NEW_INSTALL：yes表示新建，no表示使用已有harbor服务器
+# variable NEW_INSTALL: 'yes' to setup a new harbor server; 'no' to integrate with existed one 
 [harbor]
 #192.168.1.8 HARBOR_DOMAIN="harbor.yourdomain.com" NEW_INSTALL=no
 
-# 预留组，后续添加node节点使用
+# group reserved, add new 'kube-node' in it
 [new-node]
 #192.168.1.xx
 
 [all:vars]
-# ---------集群主要参数---------------
-#集群部署模式：allinone, single-master, multi-master
+# --------- Main Variables ---------------
+# Cluster Deployment Mode: allinone, single-master, multi-master
 DEPLOY_MODE=allinone
 
-#集群主版本号，目前支持: v1.8, v1.9, v1.10，v1.11
+# Versions supported: v1.8, v1.9, v1.10, v1.11, v1.12
 K8S_VER="v1.10"
 
-#集群 MASTER IP，自动生成
+# Cluster's Master IP, auto generated
 MASTER_IP="{{ groups['kube-master'][0] }}"
 KUBE_APISERVER="https://{{ MASTER_IP }}:6443"
 
-# 集群网络插件，目前支持calico, flannel, kube-router, cilium
+# Network plugins supported: calico, flannel, kube-router, cilium
 CLUSTER_NETWORK="flannel"
 
-# 服务网段 (Service CIDR），注意不要与内网已有网段冲突
+# K8S Service CIDR, not overlap with node(host) networking
 SERVICE_CIDR="10.68.0.0/16"
 
-# POD 网段 (Cluster CIDR），注意不要与内网已有网段冲突
+# Cluster CIDR (Pod CIDR), not overlap with node(host) networking
 CLUSTER_CIDR="172.20.0.0/16"
 
-# 服务端口范围 (NodePort Range)
+# NodePort Range
 NODE_PORT_RANGE="20000-40000"
 
-# kubernetes 服务 IP (预分配，一般是 SERVICE_CIDR 中第一个IP)
+# Kubernetes SVC IP (usually assigned with the first available IP of 'SERVICE_CIDR')
 CLUSTER_KUBERNETES_SVC_IP="10.68.0.1"
 
-# 集群 DNS 服务 IP (从 SERVICE_CIDR 中预分配)
+# Cluster DNS Server's IP (assigned with an available IP of 'SERVICE_CIDR')
 CLUSTER_DNS_SVC_IP="10.68.0.2"
 
-# 集群 DNS 域名
+# Cluster DNS Domain
 CLUSTER_DNS_DOMAIN="cluster.local."
 
-# 集群basic auth 使用的用户名和密码
+# Basic auth for apiserver
 BASIC_AUTH_USER="admin"
 BASIC_AUTH_PASS="test1234"
 
-# ---------附加参数--------------------
-#默认二进制文件目录
+# -------- Additional Variables --------------------
+# Binaries Directory
 bin_dir="/opt/kube/bin"
 
-#证书目录
+# CA and other components cert/key Directory
 ca_dir="/etc/kubernetes/ssl"
 
-#部署目录，即 ansible 工作目录
+# Deploy Directory (kubeasz workspace), don't change the default value right now
 base_dir="/etc/ansible"
diff --git a/example/hosts.m-masters.example b/example/hosts.m-masters.example
index 652f55c66..4d88482a8 100644
--- a/example/hosts.m-masters.example
+++ b/example/hosts.m-masters.example
@@ -1,9 +1,10 @@
-# 集群部署节点：一般为运行ansible 脚本的节点
-# 变量 NTP_ENABLED (=yes/no) 设置集群是否安装 chrony 时间同步
+# 'deploy' node, which the ansible-playbooks usually run on
+# variable 'NTP_ENABLED(=yes/no)' enables/disables the NTP server 'chrony'
 [deploy]
 192.168.1.1 NTP_ENABLED=no
 
-# etcd集群请提供如下NODE_NAME，注意etcd集群必须是1,3,5,7...奇数个节点
+# 'etcd' cluster must have odd member(s) (1,3,5,...)
+# variable 'NODE_NAME' is the distinct name of a member in 'etcd' cluster
 [etcd]
 192.168.1.1 NODE_NAME=etcd1
 192.168.1.2 NODE_NAME=etcd2
@@ -13,71 +14,71 @@
 192.168.1.1
 192.168.1.2
 
-# 负载均衡(目前已支持多于2节点，一般2节点就够了) 安装 haproxy+keepalived
+# 'loadbalance' node, with 'haproxy+keepalived' installed
 [lb]
-192.168.1.1 LB_IF="eth0" LB_ROLE=backup  # 注意根据实际使用网卡设置 LB_IF变量
+192.168.1.1 LB_IF="eth0" LB_ROLE=backup  # replace 'etho' with node's network interface
 192.168.1.2 LB_IF="eth0" LB_ROLE=master
 
 [kube-node]
 192.168.1.3
 192.168.1.4
 
-# 参数 NEW_INSTALL：yes表示新建，no表示使用已有harbor服务器
+# variable NEW_INSTALL: 'yes' to setup a new harbor server; 'no' to integrate with existed one
 [harbor]
 #192.168.1.8 HARBOR_DOMAIN="harbor.yourdomain.com" NEW_INSTALL=no
 
-# 预留组，后续添加master节点使用
+# group reserved, add new 'kube-master' in it
 [new-master]
 #192.168.1.5
 
-# 预留组，后续添加node节点使用
+# group reserved, add new 'kube-node' in it
 [new-node]
 #192.168.1.xx
 
 [all:vars]
-# ---------集群主要参数---------------
-#集群部署模式：allinone, single-master, multi-master
+# --------- Main Variables ---------------
+# Cluster Deployment Mode: allinone, single-master, multi-master
 DEPLOY_MODE=multi-master
 
-#集群主版本号，目前支持: v1.8, v1.9, v1.10，v1.11
+# Versions supported: v1.8, v1.9, v1.10, v1.11, v1.12
 K8S_VER="v1.10"
 
-# 集群 MASTER IP即 LB节点VIP地址，为区别与默认apiserver端口，设置VIP监听的服务端口8443
-# 公有云上请使用云负载均衡内网地址和监听端口
+# Cluster's Master IP, generated by 'keepalived' daemon on a 'lb' node here
+# 'haproxy' daemon listens on port 8443, directs requests to real apiservers on port 6443
 MASTER_IP="192.168.1.10"
 KUBE_APISERVER="https://{{ MASTER_IP }}:8443"
 
-# 集群网络插件，目前支持calico, flannel, kube-router, cilium
+# Network plugins supported: calico, flannel, kube-router, cilium
 CLUSTER_NETWORK="flannel"
 
-# 服务网段 (Service CIDR），注意不要与内网已有网段冲突
+# K8S Service CIDR, not overlap with node(host) networking
 SERVICE_CIDR="10.68.0.0/16"
 
-# POD 网段 (Cluster CIDR），注意不要与内网已有网段冲突
+# Cluster CIDR (Pod CIDR), not overlap with node(host) networking
 CLUSTER_CIDR="172.20.0.0/16"
 
-# 服务端口范围 (NodePort Range)
+# NodePort Range
 NODE_PORT_RANGE="20000-40000"
 
-# kubernetes 服务 IP (预分配，一般是 SERVICE_CIDR 中第一个IP)
+# Kubernetes SVC IP (usually assigned with the first available IP of 'SERVICE_CIDR')
 CLUSTER_KUBERNETES_SVC_IP="10.68.0.1"
 
-# 集群 DNS 服务 IP (从 SERVICE_CIDR 中预分配)
+# Cluster DNS Server's IP (assigned with an available IP of 'SERVICE_CIDR')
 CLUSTER_DNS_SVC_IP="10.68.0.2"
 
-# 集群 DNS 域名
+# Cluster DNS Domain
 CLUSTER_DNS_DOMAIN="cluster.local."
 
-# 集群basic auth 使用的用户名和密码
+# Basic auth for apiserver
 BASIC_AUTH_USER="admin"
 BASIC_AUTH_PASS="test1234"
 
-# ---------附加参数--------------------
-#默认二进制文件目录
+# -------- Additional Variables --------------------
+# Binaries Directory
 bin_dir="/opt/kube/bin"
 
-#证书目录
+# CA and other components cert/key Directory
 ca_dir="/etc/kubernetes/ssl"
 
-#部署目录，即 ansible 工作目录，建议不要修改
+# Deploy Directory (kubeasz workspace), don't change the default value right now
 base_dir="/etc/ansible"
diff --git a/example/hosts.s-master.example b/example/hosts.s-master.example
index e7ce7d3a4..52f8060f7 100644
--- a/example/hosts.s-master.example
+++ b/example/hosts.s-master.example
@@ -1,9 +1,10 @@
-# 集群部署节点：一般为运行ansible 脚本的节点
-# 变量 NTP_ENABLED (=yes/no) 设置集群是否安装 chrony 时间同步
+# 'deploy' node, which the ansible-playbooks usually run on
+# variable 'NTP_ENABLED(=yes/no)' enables/disables the NTP server 'chrony'
 [deploy]
 192.168.1.1 NTP_ENABLED=no
 
-# etcd集群请提供如下NODE_NAME，请注意etcd集群必须是1,3,5,7...奇数个节点
+# 'etcd' cluster must have odd member(s) (1,3,5,...)
+# variable 'NODE_NAME' is the distinct name of a member in 'etcd' cluster
 [etcd]
 192.168.1.1 NODE_NAME=etcd1
 
@@ -14,57 +15,57 @@
 192.168.1.2
 192.168.1.3
 
-# 参数 NEW_INSTALL：yes表示新建，no表示使用已有harbor服务器
+# variable NEW_INSTALL: 'yes' to setup a new harbor server; 'no' to integrate with existed one
 [harbor]
 #192.168.1.8 HARBOR_DOMAIN="harbor.yourdomain.com" NEW_INSTALL=no
 
-# 预留组，后续添加node节点使用
+# group reserved, add new 'kube-node' in it
 [new-node]
 #192.168.1.xx
 
 [all:vars]
-# ---------集群主要参数---------------
-#集群部署模式：allinone, single-master, multi-master
+# --------- Main Variables ---------------
+# Cluster Deployment Mode: allinone, single-master, multi-master
 DEPLOY_MODE=single-master
 
-#集群主版本号，目前支持: v1.8, v1.9, v1.10，v1.11
+# Versions supported: v1.8, v1.9, v1.10, v1.11, v1.12
 K8S_VER="v1.11"
 
-#集群 MASTER IP，自动生成
+# Cluster's Master IP, auto generated
 MASTER_IP="{{ groups['kube-master'][0] }}"
 KUBE_APISERVER="https://{{ MASTER_IP }}:6443"
 
-# 集群网络插件，目前支持calico, flannel, kube-router, cilium
+# Network plugins supported: calico, flannel, kube-router, cilium
 CLUSTER_NETWORK="flannel"
 
-# 服务网段 (Service CIDR），注意不要与内网已有网段冲突
+# K8S Service CIDR, not overlap with node(host) networking
 SERVICE_CIDR="10.68.0.0/16"
 
-# POD 网段 (Cluster CIDR），注意不要与内网已有网段冲突
+# Cluster CIDR (Pod CIDR), not overlap with node(host) networking
 CLUSTER_CIDR="172.20.0.0/16"
 
-# 服务端口范围 (NodePort Range)
+# NodePort Range
 NODE_PORT_RANGE="20000-40000"
 
-# kubernetes 服务 IP (预分配，一般是 SERVICE_CIDR 中第一个IP)
+# Kubernetes SVC IP (usually assigned with the first available IP of 'SERVICE_CIDR')
 CLUSTER_KUBERNETES_SVC_IP="10.68.0.1"
 
-# 集群 DNS 服务 IP (从 SERVICE_CIDR 中预分配)
+# Cluster DNS Server's IP (assigned with an available IP of 'SERVICE_CIDR')
 CLUSTER_DNS_SVC_IP="10.68.0.2"
 
-# 集群 DNS 域名
+# Cluster DNS Domain
 CLUSTER_DNS_DOMAIN="cluster.local."
 
-# 集群basic auth 使用的用户名和密码
+# Basic auth for apiserver
 BASIC_AUTH_USER="admin"
 BASIC_AUTH_PASS="test1234"
 
-# ---------附加参数--------------------
-#默认二进制文件目录
+# -------- Additional Variables --------------------
+# Binaries Directory
 bin_dir="/opt/kube/bin"
 
-#证书目录
+# CA and other components cert/key Directory
 ca_dir="/etc/kubernetes/ssl"
 
-#部署目录，即 ansible 工作目录
+# Deploy Directory (kubeasz workspace), don't change the default value right now
 base_dir="/etc/ansible"
diff --git a/roles/helm/tasks/main.yml b/roles/helm/tasks/main.yml
index 6bec8cddb..51f694707 100755
--- a/roles/helm/tasks/main.yml
+++ b/roles/helm/tasks/main.yml
@@ -14,7 +14,7 @@
 - name: 创建tiller 服务端证书请求
   template: src=tiller-csr.json.j2 dest={{ ca_dir }}/{{ tiller_cert_cn }}-csr.json
 
-- name: 创建 calico证书和私钥
+- name: 创建tiller 服务端证书和私钥
   shell: "cd {{ ca_dir }} && {{ bin_dir }}/cfssl gencert \
         -ca={{ ca_dir }}/ca.pem \
         -ca-key={{ ca_dir }}/ca-key.pem \