根据首字母或中文提示，写出正确的单词。

1. _____ is the most important thing while we are crossing the road. (安全)

2. The hall has _____ (出口) on its three sides.

3. The  _____ (士兵) died in the war were honoured as the heroes of the

country.

4. He has had his digital camera for _____ (超过) five years.

5. Before the project of Sanya , many _____ (移民) left their hometown for their new living places.

硅酸盐水泥的强度等级根据下列什么强度划分（）？

A.抗压与抗折

B.抗折

C.抗弯与抗剪

D.抗压与抗剪