直升机降落前15分钟,应停止在直升飞机坪附近()米范围内的明火作业。
A.5
B.10
C.15
D.20
参考答案:C
- What about having a cup of tea some day?
- __________.
A.Go ahead, please
B.Help yourself
C.Good idea
D.Me too
引起咽结合膜热的病原体是柯萨奇病毒。