51．arise from (=be caused by) 由……引起

52．arrange for sb./sth. to do sth. 安排……做……

53．arrive on到达；arrive at 到达某地（小地方）；得出，作出；arrive in 到达某地（大地方）；

54．be ashamed of (=feel shame, guilt or sorrow because of sth. done) 以……为羞耻

55．assure sb. of sth. (=try to cause to believe or trust in sth.) 向……保证，使……确信

56．attach(to) (=to fix, fasten; join) 缚，系，结

57． make an attempt at doing sth. (to do sth.)试图做……

58．attend to (=give one's attention, care and thought) 注意，照顾；attend on (upon) (=wait upon, serve, look after) 侍候，照料

59．attribute to/ toward ……对……的态度、看法

60．attribute……to…… (=to believe sth. to be the result of……) 把……归因于……，认为……是……的结果

61．on the average (=on average, on an average) 平均

62．(be) aware of (=be conscious of, having knowledge or consciousness) 意识到，知道