在下列各句的每个空格内填上一个适当的完整的单词，该词的首字母已给。

小题1: T he weather in South China is d           from that in North China.

小题2:My brother finished his homework all by h           .

小题3:I want to have the bike very much. But I can’t a           it.

小题4: The man has a serious i            , so he can’t go to work.

小题5: I don’t know the way to the library. Can I f            you?

截水沟在平面上布置的特点是（）

A、与水流方向平行

B、与水流方向相反

C、与水流方向垂直

D、因地形而异