10．It's _________ for you to get enough sleep every day．(有必要的)

C)请你用所给单词的适当形式填空。

9．I won't go there _________ you go．(除非)

8．There is no _________ between you and me，right?(秘密)

7．You can't drive a car if you don't have a driver's _________．(证件)

6．I'll buy a _________ for my mother's birthday．(礼物)

5．The P_________ of China is over 13 billion(十亿)．

B)请你根据句意及所给汉语提示，写出单词的正确形式。

4．My brother joined the army(军队)，because he wanted to be a s_________ in the future．

3．She is a careful girl，so she made few m_________ in the exam．

2．There are four s_________ in a year，spring，summer，autumn and winter．

A)请你根据句意及所给首字母提示，补全单词。

1．We should try out best to protect the e_________．