21 at any rate 无论如何,至少

22 at best 其量,至多

23 at first 最初,起先

24 at first sight 乍一看,初看起来

25 at hand 在手边,在附近

26 at home 在家,在国内

27 at intervals 不时,每隔...　

28 at least 至少　

29 at last 终于

30 at length 最终,终于　

31 at most 至多,不超过

32 at no time 从不,决不

33 at present 目前,现在

34 at the cost of 以...为代价

35 all means 尽一切办法,务必

36 account for 说明(原因等)

37 allow for 考虑到

38 arrive at 达成，得出

39 ask for 请求，要求

40 aim at 瞄准，针对