diff --git a/05/00_time/01/main.cpp b/05/00_time/01/main.cpp
index 42189d54..2e010d96 100644
--- a/05/00_time/01/main.cpp
+++ b/05/00_time/01/main.cpp
@@ -7,7 +7,7 @@ int main() {
     for (volatile int i = 0; i < 10000000; i++);
     auto t1 = std::chrono::steady_clock::now();
     auto dt = t1 - t0;
-    auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(dt).count();
+    int64_t ms = std::chrono::duration_cast<std::chrono::milliseconds>(dt).count();
     std::cout << "time elapsed: " << ms << " ms" << std::endl;
     return 0;
 }
diff --git a/05/00_time/02/main.cpp b/05/00_time/02/main.cpp
index 3c88fb80..78555593 100644
--- a/05/00_time/02/main.cpp
+++ b/05/00_time/02/main.cpp
@@ -3,6 +3,12 @@
 #include <chrono>
 
 int main() {
-    std::this_thread::sleep_for(std::chrono::milliseconds(400));
+    auto t0 = std::chrono::steady_clock::now();
+    for (volatile int i = 0; i < 10000000; i++);
+    auto t1 = std::chrono::steady_clock::now();
+    auto dt = t1 - t0;
+    using double_ms = std::chrono::duration<double, std::milli>;
+    double ms = std::chrono::duration_cast<double_ms>(dt).count();
+    std::cout << "time elapsed: " << ms << " ms" << std::endl;
     return 0;
 }
diff --git a/05/00_time/03/main.cpp b/05/00_time/03/main.cpp
index 292b86f2..3c88fb80 100644
--- a/05/00_time/03/main.cpp
+++ b/05/00_time/03/main.cpp
@@ -3,7 +3,6 @@
 #include <chrono>
 
 int main() {
-    auto t = std::chrono::steady_clock::now() + std::chrono::milliseconds(400);
-    std::this_thread::sleep_until(t);
+    std::this_thread::sleep_for(std::chrono::milliseconds(400));
     return 0;
 }
diff --git a/05/00_time/04/CMakeLists.txt b/05/00_time/04/CMakeLists.txt
new file mode 100644
index 00000000..1320e598
--- /dev/null
+++ b/05/00_time/04/CMakeLists.txt
@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.10)
+
+set(CMAKE_CXX_STANDARD 17)
+
+project(cpptest LANGUAGES CXX)
+
+add_executable(cpptest main.cpp)
diff --git a/05/00_time/04/main.cpp b/05/00_time/04/main.cpp
new file mode 100644
index 00000000..292b86f2
--- /dev/null
+++ b/05/00_time/04/main.cpp
@@ -0,0 +1,9 @@
+#include <iostream>
+#include <thread>
+#include <chrono>
+
+int main() {
+    auto t = std::chrono::steady_clock::now() + std::chrono::milliseconds(400);
+    std::this_thread::sleep_until(t);
+    return 0;
+}
diff --git a/05/00_time/04/run.sh b/05/00_time/04/run.sh
new file mode 100755
index 00000000..bae2e1d6
--- /dev/null
+++ b/05/00_time/04/run.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+
+cmake -B build
+cmake --build build
+build/cpptest
diff --git a/05/01_thread/02/main.cpp b/05/01_thread/02/main.cpp
index 2ed71e45..763388eb 100644
--- a/05/01_thread/02/main.cpp
+++ b/05/01_thread/02/main.cpp
@@ -19,7 +19,7 @@ void interact() {
 
 int main() {
     std::thread t1([&] {
-        download("hello.zip"); 
+        download("hello.zip");
     });
     interact();
     return 0;
diff --git a/05/01_thread/03/main.cpp b/05/01_thread/03/main.cpp
index b941dc61..e02cae39 100644
--- a/05/01_thread/03/main.cpp
+++ b/05/01_thread/03/main.cpp
@@ -19,7 +19,7 @@ void interact() {
 
 int main() {
     std::thread t1([&] {
-        download("hello.zip"); 
+        download("hello.zip");
     });
     interact();
     std::cout << "Waiting for child thread..." << std::endl;
diff --git a/05/01_thread/04/main.cpp b/05/01_thread/04/main.cpp
index 86e9e06f..e1acc982 100644
--- a/05/01_thread/04/main.cpp
+++ b/05/01_thread/04/main.cpp
@@ -19,7 +19,7 @@ void interact() {
 
 void myfunc() {
     std::thread t1([&] {
-        download("hello.zip"); 
+        download("hello.zip");
     });
     // 退出函数体时，会销毁 t1 线程的句柄！
 }
diff --git a/05/01_thread/05/main.cpp b/05/01_thread/05/main.cpp
index fb876b93..f26c7dcd 100644
--- a/05/01_thread/05/main.cpp
+++ b/05/01_thread/05/main.cpp
@@ -19,7 +19,7 @@ void interact() {
 
 void myfunc() {
     std::thread t1([&] {
-        download("hello.zip"); 
+        download("hello.zip");
     });
     t1.detach();
     // t1 所代表的线程被分离了，不再随 t1 对象销毁
diff --git a/05/01_thread/06/CMakeLists.txt b/05/01_thread/06/CMakeLists.txt
new file mode 100644
index 00000000..4800192c
--- /dev/null
+++ b/05/01_thread/06/CMakeLists.txt
@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.10)
+
+set(CMAKE_CXX_STANDARD 17)
+
+project(cpptest LANGUAGES CXX)
+
+add_executable(cpptest main.cpp)
+
+find_package(Threads REQUIRED)
+target_link_libraries(cpptest PUBLIC Threads::Threads)
diff --git a/05/01_thread/06/main.cpp b/05/01_thread/06/main.cpp
new file mode 100644
index 00000000..78c633ed
--- /dev/null
+++ b/05/01_thread/06/main.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <thread>
+#include <string>
+#include <vector>
+
+void download(std::string file) {
+    for (int i = 0; i < 10; i++) {
+        std::cout << "Downloading " << file
+                  << " (" << i * 10 << "%)..." << std::endl;
+        std::this_thread::sleep_for(std::chrono::milliseconds(400));
+    }
+    std::cout << "Download complete: " << file << std::endl;
+}
+
+void interact() {
+    std::string name;
+    std::cin >> name;
+    std::cout << "Hi, " << name << std::endl;
+}
+
+std::vector<std::thread> pool;
+
+void myfunc() {
+    std::thread t1([&] {
+        download("hello.zip");
+    });
+    // 移交控制权到全局的 pool 列表，以延长 t1 的生命周期
+    pool.push_back(std::move(t1));
+}
+
+int main() {
+    myfunc();
+    interact();
+    for (auto &t: pool) t.join();  // 等待池里的线程全部执行完毕
+    return 0;
+}
diff --git a/05/01_thread/06/run.sh b/05/01_thread/06/run.sh
new file mode 100755
index 00000000..bae2e1d6
--- /dev/null
+++ b/05/01_thread/06/run.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+
+cmake -B build
+cmake --build build
+build/cpptest
diff --git a/05/01_thread/07/CMakeLists.txt b/05/01_thread/07/CMakeLists.txt
new file mode 100644
index 00000000..4800192c
--- /dev/null
+++ b/05/01_thread/07/CMakeLists.txt
@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.10)
+
+set(CMAKE_CXX_STANDARD 17)
+
+project(cpptest LANGUAGES CXX)
+
+add_executable(cpptest main.cpp)
+
+find_package(Threads REQUIRED)
+target_link_libraries(cpptest PUBLIC Threads::Threads)
diff --git a/05/01_thread/07/main.cpp b/05/01_thread/07/main.cpp
new file mode 100644
index 00000000..8ae3b588
--- /dev/null
+++ b/05/01_thread/07/main.cpp
@@ -0,0 +1,48 @@
+#include <iostream>
+#include <thread>
+#include <string>
+#include <vector>
+
+void download(std::string file) {
+    for (int i = 0; i < 10; i++) {
+        std::cout << "Downloading " << file
+                  << " (" << i * 10 << "%)..." << std::endl;
+        std::this_thread::sleep_for(std::chrono::milliseconds(400));
+    }
+    std::cout << "Download complete: " << file << std::endl;
+}
+
+void interact() {
+    std::string name;
+    std::cin >> name;
+    std::cout << "Hi, " << name << std::endl;
+}
+
+class ThreadPool {
+    std::vector<std::thread> m_pool;
+
+public:
+    void push_back(std::thread thr) {
+        m_pool.push_back(std::move(thr));
+    }
+
+    ~ThreadPool() {                      // main 函数退出后会自动调用
+        for (auto &t: m_pool) t.join();  // 等待池里的线程全部执行完毕
+    }
+};
+
+ThreadPool tpool;
+
+void myfunc() {
+    std::thread t1([&] {
+        download("hello.zip");
+    });
+    // 移交控制权到全局的 pool 列表，以延长 t1 的生命周期
+    tpool.push_back(std::move(t1));
+}
+
+int main() {
+    myfunc();
+    interact();
+    return 0;
+}
diff --git a/05/01_thread/07/run.sh b/05/01_thread/07/run.sh
new file mode 100755
index 00000000..bae2e1d6
--- /dev/null
+++ b/05/01_thread/07/run.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+
+cmake -B build
+cmake --build build
+build/cpptest
diff --git a/05/01_thread/08/CMakeLists.txt b/05/01_thread/08/CMakeLists.txt
new file mode 100644
index 00000000..51e7a695
--- /dev/null
+++ b/05/01_thread/08/CMakeLists.txt
@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.10)
+
+set(CMAKE_CXX_STANDARD 20)
+
+project(cpptest LANGUAGES CXX)
+
+add_executable(cpptest main.cpp)
+
+find_package(Threads REQUIRED)
+target_link_libraries(cpptest PUBLIC Threads::Threads)
diff --git a/05/01_thread/08/main.cpp b/05/01_thread/08/main.cpp
new file mode 100644
index 00000000..9ae85022
--- /dev/null
+++ b/05/01_thread/08/main.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <thread>
+#include <string>
+#include <vector>
+
+void download(std::string file) {
+    for (int i = 0; i < 10; i++) {
+        std::cout << "Downloading " << file
+                  << " (" << i * 10 << "%)..." << std::endl;
+        std::this_thread::sleep_for(std::chrono::milliseconds(400));
+    }
+    std::cout << "Download complete: " << file << std::endl;
+}
+
+void interact() {
+    std::string name;
+    std::cin >> name;
+    std::cout << "Hi, " << name << std::endl;
+}
+
+// ~jthread() 解构函数里会自动调用 join()，如果 joinable() 的话
+std::vector<std::jthread> pool;
+
+void myfunc() {
+    std::jthread t1([&] {
+        download("hello.zip");
+    });
+    // 移交控制权到全局的 pool 列表，以延长 t1 的生命周期
+    pool.push_back(std::move(t1));
+}
+
+int main() {
+    myfunc();
+    interact();
+    return 0;
+}
diff --git a/05/01_thread/08/run.sh b/05/01_thread/08/run.sh
new file mode 100755
index 00000000..bae2e1d6
--- /dev/null
+++ b/05/01_thread/08/run.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+
+cmake -B build
+cmake --build build
+build/cpptest
diff --git a/05/slides.pptx b/05/slides.pptx
index 94df847e..66bb5322 100644
Binary files a/05/slides.pptx and b/05/slides.pptx differ
diff --git a/hw05 b/hw05
index e9466688..d79a47db 160000
--- a/hw05
+++ b/hw05
@@ -1 +1 @@
-Subproject commit e9466688c45d698a8835e475fc3f09aab0c53107
+Subproject commit d79a47db143e81763a94d8da4a5a27036b5b2f68