diff --git a/README.md b/README.md
index 240f51d..77f9bf6 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@
 
 笔者感谢以下读者指出本书中出现的错误：
 
-[Recolic Keghart](https://www.gitbook.com/@recolic), [sinomiko](https://www.gitbook.com/@sinomiko), [Wang Zhenhua](https://www.gitbook.com/@jackwish), [asm warrior](https://www.gitbook.com/@asmwarrior), [garicc](https://www.gitbook.com/@ihpy), [Wenhan Jiang](https://www.gitbook.com/@jiangwenhan), [liang xiao](https://www.gitbook.com/@liangx8), [slivermeteor](https://github.com/slivermeteor), [inkedawn](https://github.com/inkedawn)
+[Recolic Keghart](https://www.gitbook.com/@recolic), [sinomiko](https://www.gitbook.com/@sinomiko), [Wang Zhenhua](https://www.gitbook.com/@jackwish), [asm warrior](https://www.gitbook.com/@asmwarrior), [garicc](https://www.gitbook.com/@ihpy), [Wenhan Jiang](https://www.gitbook.com/@jiangwenhan), [liang xiao](https://www.gitbook.com/@liangx8), [slivermeteor](https://github.com/slivermeteor), [inkedawn](https://github.com/inkedawn), [zhaoyao73](https://github.com/zhaoyao73)
 
 ## 赞助
 
diff --git a/book/02-usability.md b/book/02-usability.md
index 92d1ec3..8218382 100644
--- a/book/02-usability.md
+++ b/book/02-usability.md
@@ -163,8 +163,8 @@ int main() {
     }
 
     // 需要重新定义一个新的变量
-	const std::vector<int>::iterator itr2 = std::find(vec.begin(), vec.end(), 3);
-    if (itr != vec.end()) {
+    const std::vector<int>::iterator itr2 = std::find(vec.begin(), vec.end(), 3);
+    if (itr2 != vec.end()) {
         *itr2 = 4;
     }