火灾现场的主要危险描述正确的是（）。
A、燃烧产生的毒害烟雾
B、坠落
C、倒塌
D、惊慌
参考答案：A
—Look, what an old palace! It looks so great!
—Yeah, it _____ nearly 800 years ago. [ ]
A. was building
B. was built
C. has built
D. is built
电绝缘服由（）几个部分组成。
A.上衣
B.内衣
C.背带裤
D.内裤
