第2个回答 2013-01-01
1.PREP在（某地）；在（某场合）You use at to indicate the place or event where something happens or is situated.We had dinner at a restaurant in Attleborough... 我们在阿特尔伯勒的一家餐厅里吃的饭。He will be at the airport to meet her...他将去机场接她。I didn't like being alone at home...我不喜欢一个人呆在家里。
2.PREP在（上学）If someone is at school or college, or at a particular school or college, they go there regularly to study.He was shy and nervous as a boy, and unhappy at school...他小时候既害羞又胆怯，在学校过得并不快乐。It was at university that he first encountered Hopkins...他第一次遇见霍普金斯是在上大学的时候。I majored in psychology at Hunter College.在亨特学院求学时，我主修心理学。
3.PREP在…旁边；靠近If you are at something such as a table, a door, or someone's side, you are next to it or them.An assistant sat typing away at a table beside him... 助手坐在他身旁的一张桌子上埋头打字。Graham was already at the door...格雷厄姆已经在门口了。At his side was a beautiful young woman...他旁边是个年轻漂亮的女子。
4.PREP从相隔（一段距离）的地方；呈…角度When you are describing where someone or something is, you can say that they are at a certain distance. You can also say that one thing is at an angle in relation to another thing.The two journalists followed at a discreet distance...那两个记者谨慎地保持距离跟在后面。The tree was leaning at a low angle from the ground.那棵树倾斜得非常厉害。
5.PREP在（某时间或时刻）If something happens at a particular time, that is the time when it happens or begins to happen.The funeral will be carried out this afternoon at 3.00...葬礼将在今天下午3点举行。He only sees her at Christmas and Easter.他只有在圣诞节和复活节时才能见到她。
6.PREP在（某一年龄时）；在…岁时If you do something at a particular age, you do it when you are that age.Blake emigrated to Australia with his family at 13...布莱克在13岁时随家人移民到了澳大利亚。Mary Martin has died at her home in California at the age of seventy-six.玛丽·马丁76岁时卒于加利福尼亚家中。
7.PREP以，达（某一速度、频率、水平或价格）You use at to express a rate, frequency, level, or price.I drove back down the highway at normal speed... 我以正常车速沿公路返回。Check the oil at regular intervals, and have the car serviced regularly...定期检查汽油，并对车辆进行定期维护。The submarine lies at a depth of 6,000 feet in the Barents Sea.潜艇位于巴伦支海水下6，000英尺深处。
8.PREP以，达（某一数量）You use at before a number or amount to indicate a measurement. Weighing in at eighty tons, the B-19 was easily the largest and most sophisticated warplane in the world.B-19重达80吨，无疑是世界上最大、最先进的军用飞机。...as unemployment stays pegged at three million.当失业人数维持在300万
9.PREP朝（某人或某物看）；向（某人掷物）；冲（某人说话）If you look at someone or something, you look towards them. If you direct an object or a comment at someone, you direct it towards them.He looked at Michael and laughed...他看着迈克尔笑了。The crowds became violent and threw petrol bombs at the police...人群变得狂暴起来，并向警察投掷汽油弹。A couple of people started shouting abuse at them as they walked past a pub.当他们经过一个酒吧时，有几个人开始朝他们谩骂。
10.PREP向，朝（某人微笑、招手等）You can use at after verbs such as 'smile' or 'wave' and before nouns referring to people to indicate that you have put on an expression or made a gesture which someone is meant to see or understand. She opened the door and stood there, frowning at me...她打开门站在那里，朝我皱着眉头。We waved at the staff to try to get the bill.我们向工作人员招了招手，想要买单。
11.PREP（指）向…If you point or gesture at something, you move your arm or head in its direction so that it will be noticed by someone you are with. He pointed at the empty bottle and the waitress quickly replaced it...他指了指空瓶子，女服务员立即重新拿了一瓶。He gestured at the shelves. 'I've bought many books from him.'他指着书架说，“我已经从他那里买了不少书了”。
12.PREP致力于；定位于；期望达到If you are working at something, you are dealing with it. If you are aiming at something, you are trying to achieve it.She has worked hard at her marriage.她努力维系着她的婚姻。...a $1.04m grant aimed at improving student performance on placement examinations.旨在提高学生编班考试成绩的104万美元拨款
13.PREP应（某人邀请或要求）If something is done at someone's invitation or request, it is done as a result of it. She left the light on in the bathroom at his request...她按照他的要求将浴室里的灯开着。I visited Japan in 1987 at the invitation of the Foreign Minister.应日本外相的邀请，我于1987年访问了日本。
14.PREP处在…状态You use at to say that someone or something is in a particular state or condition. I am afraid we are not at liberty to disclose that information...恐怕我们无权透露这一信息。Their countries had been at war for nearly six weeks.他们的国家陷入战争状态已将近6个星期了。
15.PREP（用于所有格代词和形容词最高级前，表示某人或某物在此时的某一特征最鲜明）You use at before a possessive pronoun and a superlative adjective to say that someone or something has more of a particular quality than at any other time. He was at his happiest whilst playing cricket...玩板球时他最开心了。Howards End is old fashioned film-making at its best.《霍华德庄园》是一部经典的老派电影。
16.PREP以…方式You use at to say how something is being done.Three people were killed by shots fired at random from a minibus...3个人被从一辆面包车中发射的乱弹打死了。Mr Martin was taken out of his car at gunpoint.马丁先生被人用枪指着从车里带了出来。
17.PREP（表示某人重复做某事）You use at to show that someone is doing something repeatedly. She lowered the handkerchief which she had kept dabbing at her eyes...她放下了那块一直用来擦眼睛的手帕。Miss Melville took a cookie and nibbled at it.梅尔维尔小姐拿起一块饼干小口吃起来。
18.PREP在…方面（擅长）You use at to indicate an activity or task when saying how well someone does it. I'm good at my work...我对自己的工作得心应手。Robin is an expert at cheesemaking...罗宾是奶酪制作专家。She excels at sport.她擅长体育运动。
19.PREP对…的反应You use at to indicate what someone is reacting to. Eleanor was annoyed at having had to wait so long for him...埃莉诺为不得不等他这么长时间而感到很恼火。The British team did not disguise their delight at their success...英国队毫不掩饰他们获胜的喜悦。Six months ago she would have laughed at the idea.要是在6个月前，她会对这个想法嗤之以鼻。
第3个回答 2013-01-01
at prep.
(表示位置) 在, 于; 到达, 达到; 经, 由; 在…旁, 靠近; 在…里; 在…上; 在…方位
He was not at his office.
他不在办公室。
(表示时间)在, 在…时刻[时辰, 期间, 阶段, 时节]; 在…岁时
The meeting will open at 15 ∶ 00.
会议在下午三点钟开始。
(表示状态)处于…状态, 在…情况下
The soldiers are standing at attention.
士兵们立正站着。
(表示方式)以…的方式; 通过一次…的动作
I was there at a bound.
我纵身一跃就到了那里。
(表示原因)因为, 由于; 由于有, 由于应…
We were frightened at the terrible sight.
看到这可怕的景象, 我们被吓呆了。
(表示距离)从, 在距离…处
I saw it at a distance.
我从远处看见了它。
(表示目标)朝, 向, 对着
He threw the key at me.
他把钥匙丢给我。
(表示环境)出席, 参加
I remember him at a banquet on that night.
我记得那天晚上他参加了一个宴会。
(表示方向)在…方面
She is good at describing things or expressing ideas.
她善于描述事物或表达思想。