28. knock into 撞上(某人)

27. safety n. 安全 safe adj. 安全的

26. develop v.（使）发展，（使）成长，（使）发达

   Doing sports can develop our health

 a developed country.  A developing country.

25. have been played 被上演   是现在完成时的被动语态

   现在完成时的被动语态的结构：have /has been +过去分词

24. including  prep. 介词  包括  可以与名词和动名词连用

   如: Six people, including a baby, were hurt.       6个人包括一个小孩受伤了。

23. more than === over 超过 如：    more than 300 == over 300 超过300

22. travel around 周游

21. in the sixth century 在第6世纪

20. throw-threw ?thrown.

   1)throw sth to sb.=throw sb sth.2)throw away 扔掉 3)throw it like that

   4)throw sth at朝   扔   5)throw sth to sb.向某人抛  6)throw about到处乱扔

   7）throw oneself somewhere.卧倒在某地

19. pleased adj. 表示外部因素引起人发自内心的欣慰和愉快

   pleasant adj. 愉快 高兴 指天气、时间、旅行令人高兴愉快

   please v. 使高兴 使同意