根据下例句中的汉语或首字母提示，写出所缺单词的正确形式(每空一词)，把答案写在题后的横线上。

1．We should exercise every morning to keep h         ．                1．          

2．She takes many good pictures with c         ．                         2．          

3．The girl w        a letter to her friend last week．               3．           

4．We shouid make a contribution to plotecting our e         ．   4．          

5．A          comes after summer                                         5．          

6．She        (留着，蓄着)long hair and has big eyes．           6．          

7．The population of the world         (增加)very fast.            7．          

8．I’m going to the dentist to have a bad tooth        (拔)out．         8．          

9．This street is one of the         (繁忙的)streets in the city．        9．          

10．My birthday is January         (九号)．                           10．