diff --git a/README.md b/README.md
index d303083..10bb30a 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@
   1. **安装Linux的环境**。对于windows的用户，推荐使用wsl2安装Ubuntu 22.04，也可以使用vmware等虚拟机进行安装。如果在这一步存在问题，请联系助教。
   2. **创建ssh key，用于ssh方式克隆github代码**。在linux环境下，使用`ssh-keygen -t rsa -b 4096 -C "你的邮箱"`命令，创建ssh key，下面的选项全部直接敲回车即可。 随后使用` cat ~/.ssh/id_rsa.pub` 命令查看生成的公钥，并完整的复制下来。 在github仓库界面点击自己的头像，选择`settings`。进入到设置页面后，点击左侧的`SSH and GPG keys`选项。点击`New SSH key`选项，并将复制下来的内容粘贴上去，添加该ssh key的描述。随后点击`Add SSH key`，并一路点击确认即可。
   3. **本地安装rust**。进入linux环境下，参考Arceos 教程 [Rust 开发环境配置 - ArceOS Tutorial Book (rcore-os.cn)](https://rcore-os.cn/arceos-tutorial-book/ch01-02.html) 中，找到Rust 开发环境配置的章节，相应配置即可，你可以同时将后续需要的环境也配置好.
-  4. **clone实验仓库到本地。**在前面点击链接生成的仓库中，同样点击醒目的 `code` 绿色按钮，选择`local`下的`ssh`选项，复制下面的链接。随后回到本地linux环境下，使用`git clone 复制的链接`的方式，将目标仓库clone到本地。随后，使用`ls`命令查看自己clone下来的文件夹，再使用`cd`命令进入到该文件夹下，使用  `cargo install --force --path .`  安装rustlings。
+  4. **clone实验仓库到本地。** 在前面点击链接生成的仓库中，同样点击醒目的 `code` 绿色按钮，选择`local`下的`ssh`选项，复制下面的链接。随后回到本地linux环境下，使用`git clone 复制的链接`的方式，将目标仓库clone到本地。随后，使用`ls`命令查看自己clone下来的文件夹，再使用`cd`命令进入到该文件夹下，使用  `cargo install --force --path .`  安装rustlings。
   5. **练习rustlings**。使用vscode等编辑器，进入clone下来的目录下的`exercises`文件夹，执行`rustlings watch`依次查看完成情况，并依次完成对应的练习。 执行`rustlings run 练习名称`去运行对应练习，也可以使用`rustlings hint 练习名称`查看题解。
   6. **提交完成情况**。当做完部分或所有练习之后，在rustlings目录下执行 `git add .; git commit -m "update"; git push` 命令，把更新提交到GithubClassroom的CI进行自动评测。你可以在github仓库页面的actions页面，看到你的CI提交结果，或者 https://opencamp.ai/Rust/camp/S01/stage/0?tab=rank 上面查看自己的评分。
 * 在线环境：
diff --git a/exercises/functions/functions1.rs b/exercises/functions/functions1.rs
index 40ed9a0..770d4a9 100644
--- a/exercises/functions/functions1.rs
+++ b/exercises/functions/functions1.rs
@@ -2,8 +2,9 @@
 //
 // Execute `rustlings hint functions1` or use the `hint` watch subcommand for a
 // hint.
-
-// I AM NOT DONE
+fn call_me(){
+    
+}
 
 fn main() {
     call_me();
diff --git a/exercises/functions/functions2.rs b/exercises/functions/functions2.rs
index 5154f34..318f80d 100644
--- a/exercises/functions/functions2.rs
+++ b/exercises/functions/functions2.rs
@@ -3,13 +3,12 @@
 // Execute `rustlings hint functions2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     call_me(3);
 }
 
-fn call_me(num:) {
+fn call_me(num:i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }
diff --git a/exercises/functions/functions3.rs b/exercises/functions/functions3.rs
index 74f44d6..0a01731 100644
--- a/exercises/functions/functions3.rs
+++ b/exercises/functions/functions3.rs
@@ -3,10 +3,9 @@
 // Execute `rustlings hint functions3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    call_me();
+    call_me(3);
 }
 
 fn call_me(num: u32) {
diff --git a/exercises/functions/functions4.rs b/exercises/functions/functions4.rs
index 77c4b2a..96891ce 100644
--- a/exercises/functions/functions4.rs
+++ b/exercises/functions/functions4.rs
@@ -8,14 +8,13 @@
 // Execute `rustlings hint functions4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     let original_price = 51;
     println!("Your sale price is {}", sale_price(original_price));
 }
 
-fn sale_price(price: i32) -> {
+fn sale_price(price: i32) -> i32 {
     if is_even(price) {
         price - 10
     } else {
diff --git a/exercises/functions/functions5.rs b/exercises/functions/functions5.rs
index f1b63f4..c51bea9 100644
--- a/exercises/functions/functions5.rs
+++ b/exercises/functions/functions5.rs
@@ -3,13 +3,11 @@
 // Execute `rustlings hint functions5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     let answer = square(3);
     println!("The square of 3 is {}", answer);
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }
diff --git a/exercises/if/if1.rs b/exercises/if/if1.rs
index d8108a0..a0285f1 100644
--- a/exercises/if/if1.rs
+++ b/exercises/if/if1.rs
@@ -2,13 +2,18 @@
 //
 // Execute `rustlings hint if1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn bigger(a: i32, b: i32) -> i32 {
     // Complete this function to return the bigger number!
     // Do not use:
     // - another function call
     // - additional variables
+    if a>=b{
+        a
+    }
+    else{
+        b
+    }
 }
 
 // Don't mind this for now :)
diff --git a/exercises/if/if2.rs b/exercises/if/if2.rs
index f512f13..2887762 100644
--- a/exercises/if/if2.rs
+++ b/exercises/if/if2.rs
@@ -5,13 +5,14 @@
 //
 // Execute `rustlings hint if2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 pub fn foo_if_fizz(fizzish: &str) -> &str {
     if fizzish == "fizz" {
-        "foo"
-    } else {
-        1
+        return "foo";
+    }
+    if fizzish == "fuzz" {
+        return "bar";
+    }else{
+        return "baz";
     }
 }
 
diff --git a/exercises/if/if3.rs b/exercises/if/if3.rs
index 73a7025..d81f7bb 100644
--- a/exercises/if/if3.rs
+++ b/exercises/if/if3.rs
@@ -2,17 +2,16 @@
 //
 // Execute `rustlings hint if3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn animal_habitat(animal: &str) -> &'static str {
     let identifier = if animal == "crab" {
         1
     } else if animal == "gopher" {
-        2.0
+        2
     } else if animal == "snake" {
         3
     } else {
-        "Unknown"
+        4
     };
 
     // DO NOT CHANGE THIS STATEMENT BELOW
diff --git a/exercises/intro/intro2.rs b/exercises/intro/intro2.rs
index 990b20f..6c3f638 100644
--- a/exercises/intro/intro2.rs
+++ b/exercises/intro/intro2.rs
@@ -5,8 +5,7 @@
 // Execute `rustlings hint intro2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    println!("Hello {}!");
+    println!("Hello world!");
 }
diff --git a/exercises/quiz1.rs b/exercises/quiz1.rs
index a9904b8..5980acc 100644
--- a/exercises/quiz1.rs
+++ b/exercises/quiz1.rs
@@ -13,10 +13,16 @@
 //
 // No hints this time ;)
 
-// I AM NOT DONE
 
 // Put your function here!
-// fn calculate_price_of_apples {
+fn calculate_price_of_apples(num:i32) -> i32 {
+    if num > 40{
+        num
+    }else{
+        num*2
+    }
+
+}
 
 // Don't modify this function!
 #[test]
diff --git a/exercises/variables/variables1.rs b/exercises/variables/variables1.rs
index b3e089a..469fd4e 100644
--- a/exercises/variables/variables1.rs
+++ b/exercises/variables/variables1.rs
@@ -5,9 +5,8 @@
 // Execute `rustlings hint variables1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    x = 5;
+    let x = 5;
     println!("x has the value {}", x);
 }
diff --git a/exercises/variables/variables2.rs b/exercises/variables/variables2.rs
index e1c23ed..59f9a02 100644
--- a/exercises/variables/variables2.rs
+++ b/exercises/variables/variables2.rs
@@ -3,10 +3,8 @@
 // Execute `rustlings hint variables2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
-    let x;
+    let x = 10;
     if x == 10 {
         println!("x is ten!");
     } else {
diff --git a/exercises/variables/variables3.rs b/exercises/variables/variables3.rs
index 86bed41..c40cf3a 100644
--- a/exercises/variables/variables3.rs
+++ b/exercises/variables/variables3.rs
@@ -3,9 +3,8 @@
 // Execute `rustlings hint variables3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x: i32;
+    let x: i32 = 1;
     println!("Number {}", x);
 }
diff --git a/exercises/variables/variables4.rs b/exercises/variables/variables4.rs
index 5394f39..2d056da 100644
--- a/exercises/variables/variables4.rs
+++ b/exercises/variables/variables4.rs
@@ -3,10 +3,9 @@
 // Execute `rustlings hint variables4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {}", x);
     x = 5; // don't change this line
     println!("Number {}", x);
diff --git a/exercises/variables/variables5.rs b/exercises/variables/variables5.rs
index a29b38b..19ce9d6 100644
--- a/exercises/variables/variables5.rs
+++ b/exercises/variables/variables5.rs
@@ -3,11 +3,9 @@
 // Execute `rustlings hint variables5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     let number = "T-H-R-E-E"; // don't change this line
     println!("Spell a Number : {}", number);
-    number = 3; // don't rename this variable
+    let number = 3; // don't rename this variable
     println!("Number plus two is : {}", number + 2);
 }
diff --git a/exercises/variables/variables6.rs b/exercises/variables/variables6.rs
index 853183b..53ebf53 100644
--- a/exercises/variables/variables6.rs
+++ b/exercises/variables/variables6.rs
@@ -3,9 +3,8 @@
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
-const NUMBER = 3;
+const NUMBER:i32 = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }