1. at full speed  [全速]
[构成]:at[在] + full[满的；完全的] + speed[速度]
例句：The car was running at full speed. [汽车全速行驶。]

2. at random  [随机；任意]
[构成]:at[在] + random[随机的]
例句：The names were chosen at random. [这些名字是随机选取的。]

3. at ease  [自在；舒适]
[构成]:at[在] + ease[轻松；自在]
例句：He felt at ease after the exam. [考试后他感到轻松自在。]

4. at hand  [在手边；即将到来]
[构成]:at[在] + hand[手]
例句：The materials you need are at hand. [你需要的材料就在手边。]

5. at fault  [有错；有责任]
[构成]:at[在] + fault[错误；故障]
例句：Who is at fault in this accident? [这次事故谁有责任？]

6. at war  [处于交战状态]
[构成]:at[在] + war[战争]
例句：The two countries were at war. [这两个国家处于交战状态。]

7. at risk  [处于危险中]
[构成]:at[在] + risk[风险；危险]
例句：His life is at risk. [他的生命处于危险之中。]

8. at will  [随意；任意]
[构成]:at[在] + will[意愿；意志]
例句：You can come and go at will. [你可以随意来去。]

9. at sight  [一看到就]
[构成]:at[在] + sight[视力；景象]
例句：The dog barked at sight of the stranger. [狗一看到陌生人就叫。]

10. at best  [至多；充其量]
[构成]:at[在] + best[最好的]
例句：The plan is at best only a partial solution. [这个计划充其量只是部分解决办法。]

11. at large  [逍遥法外；一般；总体上]
[构成]:at[在] + large[大的；大规模的]
例句：The thief is still at large. [那个小偷仍逍遥法外。]

12. at intervals of  [每隔]
[构成]:at[在] + intervals[间隔] + of[的]
例句：The buses come at intervals of 10 minutes. [公共汽车每隔 10 分钟来一辆。]

13. at one's disposal  [供某人使用；由某人支配]
[构成]:at[在] + one's[某人的] + disposal[处理；支配]
例句：The car is at your disposal. [这辆车供你使用。]

14. at one's wit's end  [不知所措；智穷力竭]
[构成]:at[在] + one's[某人的] + wit's[智慧的] + end[尽头]
例句：I'm at my wit's end with this problem. [这个问题让我不知所措。]

15. at one stroke  [一下子；一举]
[构成]:at[在] + one[一] + stroke[一击；一笔]
例句：He solved the problem at one stroke. [他一下子解决了这个问题。]

16. at the mercy of  [受...支配；任凭...摆布]
[构成]:at[在] + the[定冠词] + mercy[仁慈；怜悯] + of[的]
例句：They were at the mercy of the weather. [他们受天气的摆布。]

17. at a glance  [一眼；看一眼]
[构成]:at[在] + a[一个] + glance[一瞥；扫视]
例句：I knew the answer at a glance. [我一眼就知道了答案。]

18. at a stretch  [一口气；连续地]
[构成]:at[在] + a[一个] + stretch[伸展；连续]
例句：He worked for six hours at a stretch. [他一口气工作了六个小时。]

19. at a premium  [奇缺的；珍贵的]
[构成]:at[在] + a[一个] + premium[保险费；溢价]
例句：Good parking spaces are at a premium in the city centre. [市中心好的停车位很珍贵。]

20. at any price  [不惜任何代价]
[构成]:at[在] + any[任何] + price[价格]
例句：He wanted to win at any price. [他不惜任何代价都想赢。]