根据句意，用括号内所给单词的适当形式填空。

1. — What will you do when you are in _____ (dangerous)? 

    — I'll call 110.

2. He was there for a long time without _____ (do something).

3. We all know work must come _____ (one).

4.Thanks for _____ (listen) to my talk.

5. I _____ (begin) to study English two years ago.

企业特种作业人员必须根据安全生产的规定持证上岗，一经发现施工单位特种作业使用无证人员施工的，（）。

A、吊销施工执照

B、处以罚款

C、限期整改

D、责令停工整顿