根据答句写问句。

1. A:___                                     _?

    B: My ruler is 20 cm long.

2. A:                                             ?

    B: I have a headache.

3. A: ___                                     _?

    B: I went to a park yesterday.

4. A:____                                     ?

    B: I bought many presents on my holiday.

5. A:__                                      __?

    B: He went there by bike.

属于遗传毒性致癌物的是（）

A.铬及其化合物、镍及其化合物、烟灰和焦油（含多环芳烃）、双氯甲醚

B.镍及其化合物、石棉、烟灰和焦油（含多环芳烃）、双氯甲醚

C.佛波酯

D.石棉

E.氯仿