16. (次数)+every… 每隔……(次)

　　 Take this medicine once every four hours. 这药每隔三小时吃一次。(即每四小时一次)　

　　 He comes here every three days.他每隔两天来这儿一次。(即每三天来这一次)

　　 讲“一天、一年、一月、一周、一小时的几次”时不用every，而用a。

　　 The doctor asked him to take the medicine three times a day.医生要他每天服药三次。

15.over zero centigrade零度以上

14.more than=not only不只是，不仅仅

　　 He is more than a reporter, he is a fighter for freedom.他不仅是个记者，他还是一位捍卫自由的战士。

　　 注意：more than还有“多于”的意思。

　 　I went more than a kilometre alone.

13.keep fairly warm保持相当暖和

12.have no choice but to do 别无选择，只得

　　 On cold winter days some animals have no choice but lie down and sleep.

　　 In order to make more money to support his large family, he had no choice but to work day and night.

　　 注意介词but后用动词原形，但在do nothing but 中，介词but后用原形。试对比：

　　 There was no bus, so they had no choice but to walk home.

　　 There was no bus, so they didn't do anything but walk home.

11.in the usual way以通常的方式

10.below freezing冰点以下

9.keep up=remain,continue 保持，维持，继续

　　 You have done very well so far, I hope you can keep it up.

　　 Will the fine weather keep up?

　　 I'm glad that you are keeping up your piano practice.你在继续练钢琴，我很高兴。

　　 keep up 表“继续”时与keep on ,go on同义。但keep up 后面常接名词，keep on,go　 on后常接动名词。

8.lead/live a(…)life过着……的生活。

　　 They led a cat's and dog's life before liberation.解放前他们过着牛马不如的生活。

　　 They lived a miserable life.他们过着悲惨的生活。

　　 注意在lead/live…life中的形容词可以根据需要作出相应的变化。如：

　　 lead an active life过着自由自在的生活，lead an exciting life过着令人激动的生活，live a happy life 过着幸福的生活，lead a hard/rough life 过着艰难的日子

7.keep out=prevent from entering 阻止不让进人员；置身……之外

　　 Shut the windows and keep the cold out.

　　 Warm clothing will keep us the cold out.

　　 Danger! Keep out!

　　 I hope you'll keep him out of trouble while I'm away. 我希望我不在的时候，你不要让他惹是生非。