diff --git "a/3\354\236\245/3.2.4-2.ts" "b/3\354\236\245/3.2.4-2.ts"
index 3b3ed90..5c06f12 100644
--- "a/3\354\236\245/3.2.4-2.ts"
+++ "b/3\354\236\245/3.2.4-2.ts"
@@ -1,9 +1,8 @@
 const PromotionList = [
   { type: "product", name: "chicken" },
   { type: "product", name: "pizza" },
-  { type: "card", name: "chee-up" },
+  { type: "card", name: "cheer-up" },
 ];
 
-type ElementOf<T> = (typeof T)[number];
 // type PromotionItemType = { type: string; name: string }
-type PromotionItemType = ElementOf<PromotionList>;
+type PromotionItemType = typeof PromotionList[number];
diff --git "a/9\354\236\245/9.2.1-2.jsx" "b/9\354\236\245/9.2.1-2.jsx"
index ba34d57..5de6960 100644
--- "a/9\354\236\245/9.2.1-2.jsx"
+++ "b/9\354\236\245/9.2.1-2.jsx"
@@ -4,9 +4,9 @@ const MyComponent = () => {
   return (
     <div>
       <h1>{value}</h1>
-      <input onChange= {onChange} value= {text} />
+      <input onChange= {onChange} value= {value} />
     </div>
   );
 };
 
-export default App;
\ No newline at end of file
+export default MyComponent;
\ No newline at end of file