diff --git a/lesson-2/.DS_Store b/lesson-2/.DS_Store
new file mode 100644
index 0000000..76285f8
Binary files /dev/null and b/lesson-2/.DS_Store differ
diff --git a/lesson-4/chapter-1/ownable.sol b/lesson-4/chapter-1/ownable.sol
index 61be7b4..edb7953 100644
--- a/lesson-4/chapter-1/ownable.sol
+++ b/lesson-4/chapter-1/ownable.sol
@@ -1,6 +1,6 @@
 pragma solidity ^0.4.25;
 
-/**
+/**เริ่มซับซ้อน เกี่ยวกับเจ้าของ
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".