diff --git a/docs/系统安全/CS161.en.md b/docs/系统安全/CS161.en.md
index fefb5ed0..33557898 100644
--- a/docs/系统安全/CS161.en.md
+++ b/docs/系统安全/CS161.en.md
@@ -16,9 +16,9 @@ Computer Security course from UC Berkeley, devided into 5 parts:
 - Web: SQL-injection, XSS, XSRF .......
 - Networking: attacks for each layer
 
-The most impressive part to me is Project2, which requires you to  design and implement a secure file sharing system in Go. It took me three full days to complete this extremely difficult project, with over 3 thousand lines of code. Such an intensive development process can greatly hone your ability to design and implement a secure system.
+The most impressive part to me is Project2, which requires you to design and implement a secure file sharing system in Go. It took me three full days to complete this extremely difficult project, with over 3 thousand lines of code. Such an intensive development experience can greatly enhance your ability to design and implement a secure system.
 
-2020 summer semester posted its vedio recordings publicly, which can be found from links below.
+In 2020 summer semester, the lecture recordings are posted publicly, which can be found in the links below.
 
 ## Course Resources