Unit 13
                                同步练习
  Ⅰ. 单词拼写。
  1. Do you know that ants have two ______(胃).
  2. Though he is over 70, he is still full of ______(精力).
  3. Are you feeling tired? You look______(困乏的).
  4. Don’t use the machine unless _______(检查).
  5. Don’t drink _____(煮沸) water, or you may get burned.
  6. Gas, petrol, coal all belong to f______.
  7. You look thinner. Are you losing w_____?
  8. It’s important to keep the b_______ of nature.
  9. She decided to go on a d____, for she was too fat.