看看你的应变能力，用所给单词的适当形式填空。

1.He is going to ____(buy)a bike.

2.Mary ____(grow)some vegetables in her garden.

3.-What are you doing?

  -I ____ (write) a letter.

4.Mary's books are good for ____ (garden).

5.I ____ (see) this novel already.

肺结核咯血的最常见原因为（）

A.病灶钙化

B.病灶形成纤维化

C.渗出和空洞病变

D.病灶出现硬结

E.血小板减少