67.　　 at this time of (the ) day 在这时

66.　　 at the same time 同时

65.　　 at the moment 此刻；正当那时

64.　　 at the end of … 结束时(终点)

63.　　 at the beginning of …起初，开始　

62.　　 at the age of 在…岁时

61.　　 at the front / back of 在…的前部 / 后边

60.　　 argue with sb.与某人争论

59.　　 at least 至少

58.　　 at last(finally, in the end)最后