diff --git a/2-ui/1-document/09-size-and-scroll/article.md b/2-ui/1-document/09-size-and-scroll/article.md
index 952dd727..774857f3 100644
--- a/2-ui/1-document/09-size-and-scroll/article.md
+++ b/2-ui/1-document/09-size-and-scroll/article.md
@@ -64,7 +64,7 @@ The `offsetParent` is the nearest ancestor that is:
2. or `
`, ` | `, ``,
2. or ``.
-In most practical cases we can use `offsetParent` to get the nearest CSS-positioned ancestor. And `offsetLeft/offsetTop` provide x/y coordinates relative to it's upper-left corner.
+In most practical cases we can use `offsetParent` to get the nearest CSS-positioned ancestor. And `offsetLeft/offsetTop` provide x/y coordinates relative to its upper-left corner.
In the example below the inner `` has `` as `offsetParent` and `offsetLeft/offsetTop` shifts from its upper-left corner (`180`):
|