attend to give attention to,注意；专心
Please attend to what I'll tell you．请注意我要讲的话。
He attended to his business．他专心于他的事务。
attend to give help to ； take care of ；deal with照料；护理；处理
I have a lot of things to attend to．我有许多事情要处理。
Would you please attend to the child when I am off to work？我上班时，你照看一下这孩子，好吗？
attribute to 认为是…的缘故；归于
Jack attributed his success to hard work．杰克认为自己的成功来自于刻苦努力。
He attributes his good health to careful living．他的健壮的体魄归因于他注意妥善安排生活。
attribute to 认为…为某人所作
The poem is usually attributed to Libai．这首诗通常被认为是李白的作品。
avail oneself of 利用
You should avail yourself of every chance to improve your spoken English．你应当利用一切机会提高英语口语水平。
avenge of 报复；复仇
The King was avenged of his father's murder．国王报了杀父之仇。
avenge on take vengeance for为（某人）向（某人）报复
The King avenged his father on his uncle．国王向叔父报了杀父之仇。
average out reach an average达到某一平均数
His taxes may average out at about one quarter of his income．他的税可能平均达到他收入的四分之一左右。
Their working hours average out at forty per week．他们每周的工作时间平均达到四十小时。
average out 算出平均数
They averaged out the numbers and got the result twenty-five．他们算了这些数的平均数，结果是二十五。
awake to begin to understand；become watchful about认识；明白
We must awake to the dangers facing our country．我们必须认识到国家所面临的危难。
You must awake to the fact that failure is the mother of success．你必须明白失败是成功之母。
aware of conscious of 知道；意识到
He is not aware of the fact that life is hard．他不知道生活是艰难的。
He was not aware of his having done wrong．他没意识到他做错了。
Presently she became aware of footsteps hurrying after her．过了一会她发觉身后有脚步声匆忙追来。
back and forth . backwards and forwards； to and from； up and down来来回回地
She walked back and forth on the path．她在小径上来回走着。
back away . draw back ； move backwards后退；移开
The crowd backed away to let the queen's carriage pass through．人群退开了，好让女王的车子过去。
back down 背朝后下降
He backed down carefully，while I held the ladder for him．我给他扶梯子，他小心地爬下来。
The car at the top of the slope backed slowly down．坡顶上的那辆汽车慢慢地退下来。
back down . give away；yield.放弃；让步
He backed down and accepted our proposal．他放弃了原有想法，接受了我们的建议。
The trade union expects the management to back down． 工会希望资方能够让步。
He was too proud to back down and admit mistakes．他傲气十足，不肯让步和承认错误。
back out 撤回协议或契约；退出
If you back out from the contract，you will have to pay a large sum of money to the company．如果你违背协议，就得向公司支付一大笔钱。
She backed out of her engagement．她不履行婚约。
back out 食言；收回承担的责任
He agreed to lend me the money，but backed out later．他答应借钱给我的，可是后来变卦了。
at the last minute， John backed out and refused to go with us．最后一分钟时，约翰变卦了，不同意和我们一起去。
He backed out because there was not much profit in this undertaking．由于这项事业效益不大，他中途退出了。
back up .drive backwards . move backwards.倒车
He had to back his car up because the mountain path was too narrow．由于山路太窄，他不得不把车子倒了回来。
back up .support 支持
I hope you will back me up in this argument．我希望在这场争论中你能支持我。
Nobody backed her up when she protested against the decision．当她反对这项决定时，没人支持她。
back up .block； hold up阻塞
The vehicles were backed up because of the accident．车辆因交通事故受阻了。
badly off. poor；short of贫穷；缺少
My family was badly off in those days．在那些日子里，我家很穷。
The school is now badly off for experienced teachers．这所学校现在缺少有经验的教师。
bang away. shoot continuously连续射击
The soldiers were banging away at the target．士兵们不停地向靶子射击。
bang into . collide with 碰撞
He banged into a bus on the street．他在大街上撞到一辆公共汽车上了。
The bus banged into a wall．汽车猛撞到墙上。
bang into . meet by chance偶然相遇
I didn't expect to bang into him again．我没有想到能再次碰到他。