66. turn one’s back on sb. (=turn away from sb. in an impolite way) 不理睬(某人),背弃,抛弃　­

65. at one’s back(=supporting or favoring sb.) 支持,维护; have sb. at one ’s back 有…支持, 有…作后台　­

64. in the back of 在…后部(里面); on the back of 在…后部(外面); be on one’s back(=be ill in bed) 卧病不起.　­

63. at the back of (=behind) 在…后面　­

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

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

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

59. attitude to toward …对…的态度.看法　­

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　­

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