在下列各句的空格内填上一个适当的完整的单词，该词的首字母已给出。

1. He has v_________ a lot of places since he came to Ningbo.

2. When summer comes, day becomes longer and n_________ becomes shorter.

3. It's our duty to help b_________ people because they aren't able to see.

4. Hurry up, or we won't c_________ the early bus.

5. P_________ are my favorite animals and they live only in China.

主要引起膀胱癌的物质为（）

A.铬酸盐

B.氯甲醚

C.芥子气

D.煤焦油

E.联苯胺