Ø make an attempt at doing sth (to do sth) 试图做…
　　 If you make an attempt to do something, you try to do it, often without success.
　　 Ø attend to (=look after) 关注；注意：
　　 We’ll attend to that problem later.
　　 稍后我们将关注那个问题
　　 The staff will helpfully attend to your needs.
　　 Ø attend on(upon)(=wait upon, serve) 侍候
　　 attend on one’s master 侍候主人
　　 Ø attitude to/ toward …对…的态度/看法
　　 People’s attitude towards the skyscrapers varies widely. 人们对这些摩天大楼的态度很不相同。
　　 Ø attribute…to…(=to believe sth to be the result of…)把…归因于
　　 David attributed his company’s success to the unity of all the staff and their persevering hard work.
　　 大卫说他们公司之所以获得成功是由于全体员工的团结和坚持不懈努力工作的结果。
　　 Ø on the average (=on average, on an average) 平均
　　 On average, American firms remain the most productive in the world.
　　 American shares rose, on average, by 38%.
　　 Ø be aware of (=be conscious of , beware)意识到
　　 I was not aware of the fire. 我没有意识到火。
　　 Ø in the back of在...后面 支持, 主使
　　 Actor Hugh Grant was caught with his pants down when he was having sex with a prostitute in the back of his car.
　　 Ø on the back of 在…后部(外面);
　　 A guy is reading his paper when his wife walks up behind him and smacks him on the back of the head with a frying pan.
　　 be on one’s back(=be ill in bed) 卧床
　　 He lay on his back, with his hands crossed under his head.他仰面躺着,头枕着手。
　　 Ø at one’s back(=supporting or favoring sb) 支持
　　 Don’ t talk about other’ s at his
　　 back.
　　 A:Tom should learn to look after himself.
　　 B:Yeah,he can’t always have us at his back.
　　 Ø have sb at one’s back 有…支持, 有…作后台
　　 Ø behind one’s back 背着某人(说坏话)
　　 Don’t speak evil of a man behind his back．
　　 不要在背后说人坏话。
　　 Ø turn one’s back on sb (=close one’s eye to sb) 不理睬(某人),背弃,抛弃
　　 If the world turns its back on you, you turn your back on the world.
　　 Ø be based on / upon 基于
　　 This news report is based entirely on fact.
　　 这篇新闻报导是完全根据实际情况写成的。
　　 Ø on the basis of 根据…, 在…基础上
　　 On the basis of the above results, we may establish attractor viewpoint of process of the long-range atmosphere and climate.
　　 Ø begin with 以…开始
　　 Knowledge begin with practice. 认识从实践开始。
　　 Ø To begin with (=firstly) 首先, 第一(经常用于开始语)
　　 To begin with, we must consider the faculties of the staff all-sidedly.首先,我们必须全面地考虑全体员工的素质。