根据句意及首字母提示完成句子。

1. Chinese is different from English in many w______.

2. Grandma fell i______yesterday, we took her to a hospital.

3. I saw an old man f______ off his bike just now.

4. It is well known that Yao Ming is a p_____basketball player.

5. Look! The dog is playing w______the cat.

6. Yesterday my friend lost her p______, but there was much money in it.

7. Head is a part of person's b______.

8. —When did you r______ your friend's letter? —Yesterday.

选择地表水作为给水水源时，其枯水期的保证率不得低于( )。

A．60%
B．70%
C．80%
D．90%