两个因数分别是63和4，积是______，如果因数4扩大10倍、100倍，那么积分别是______．

单句改错

1. It is a lot more excited to travel by air than by  water.        

2. You can see falling leaves everywhere in autumn.        

3. On arriving home, she found her husband looked worried.        

4. Losing in thought,he didn't hear what his teacher said at all.