根据句意和汉语提示完成单词。

1. How many                (书本) are there in your schoolbag?

2. Can you                 (骑) horse?

3. My brother is a                (医生) in a hospital.

4. My hobby is playing               (篮球).

5. Shally                (喜欢) playing the piano.

钙的缺乏将导致骨质疏松。