20. keep healthy 保持健康=be healthy =stay healthy=keep fit

    be in good health   keep in good healthy

19. most of … …的大多数

18. energy n. 活力  energetic adj. 有活力的

17. over the years 很多年来，常与现在完成时连用如：

Over the years, they’ve planted many trees on the hills.

多年来他们已在山上种植了许多树。

16. on display 展览=on show =on exhibition

15. known adj. 有名的 著名的  know v. 知道 认识

14. be sure to do 一定做某事 肯定做某事 如：

   It is sure to snow. 肯定要下雪 

 Be sure not to forget it. 千万不要忘记呀!

13. fun n. 有趣   funny adj. 有趣的

12. though == although 作连词  虽然，尽管

放在句子中间/句首，不能和but 连用

Though it was very late, he went on working. 虽然很晚了，但他还在工作

Mr. Smith , though he was young, did it very well.

史密斯先生虽然年轻，却做得很好。

11. look for 寻找

  My pen is lost. Could you help me look for it?

我的笔丢了。你能帮我找一下吗？