1. 根据句意和汉语或首字母提示补全单词。

1. （1） He felt  (生病的) and fell down after running in the hot sun.

3. （2） Put your head down and press the sides of your nose if you have a n.

5. （3） He likes to climb mountains to b the fresh air.

7. （4） He found himself in a very dangerous  (情况) when the  rainstorm came.

9. （5） We should know the  (重要性) of good decisions.