1. a fraction of 一部分
2. a matter of concern 焦点
3. a series of 一系列,一连串
4. above all 首先,尤其是
5. absent from 不在,缺席
6. abundant in 富于
7. account for 解释
8. accuse sb. of sth.控告
9. add to 增加(add up to)
10. after all 毕竟,究竟
11. agree with 同意
12. ahead of time / schedule提前
13. ahead of 在...之前(ahead of time 提前)
14. alien to 与...相反
15. all at once 突然,同时
16. all but 几乎;除了...都
17. all of a sudden 突然
18. all over again 再一次,重新
19. all over 遍及
20. all right 令人满意的;可以
21. all the same 仍然,照样的
22. all the time 一直,始终
23. angry with sb. at/about sth.生气,愤怒
24. anxious about/for 忧虑,担心
25. anything but 根本不
26. apart from 除...外(有/无)
27. appeal to 吸引，申诉，请求
28. applicable to 适用于
29. apply to 适用
30. appropriate for/to 适当,合适
31. approximate to 近似,接近
32. apt at 聪明,善于
33. apt to 易于
34. around the clock 夜以继日
35. as a matter of fact 实际上
36. as a result(of) 因此,由于
37. as a rule 通常,照例
38. as far as ...be concerned 就...而言
39. as far as 远至,到...程度
40. as follows 如下
41. as for 至于,关于
42. as good as 和...几乎一样
43. as if 好像,仿佛
44. as regards 关于,至于
45. as to 至于,关于
46. as usual 像平常一样,照例
47. as well as 除...外(也),即...又
48. as well 同样,也,还
49. ashamed of 羞愧,害臊
50. aside from 除...外(还有)