assembly n. 集合, 装配, 集会(assembly line/装配线);
assess v. 评估(财产, 价值, 人物、工作等); (assess – evaluate – value评估)
assist v. (在某方面)帮助，援助，协助 ((assist sb. in doing sth/to do sth/在…方面帮助某人))
assistant n. 助手, 助理(assistant engineer/助理工程师; assistant professor/副教授);
associate v. 结交, 由...联想到..., 把...联系起来(associate one thing with another/把某一事与另一事联系起来; ...be associated with sth./...和...有关/...和...有联系):
association n. 联合,协会, 社团:
assume v. 假设(assume – suppose ),承担(assume – take on - acccept), 呈(态度, 姿态, 位置) (assume new duties/承担新的职务; assume office/就职; assume responsibility/负责, 承担责任);
assure v. 保证 (assume - ensure) ，使安心，让…放心 (assure sb. of/that…/向某人保证…)
astonish v. 使吃惊(astonish – surprise –shock)(be astonished at sth. /对…感到惊讶);
astronaut n. 宇航员
at prep.[位置， 场所， 地点，时间]在…时，在…中，在…方面，向，(表示速度，价格等)以(arrive at…/到达…; at my uncle's/在我叔父家;at the foot[top] of the mountain /在山脚下[顶上]; at the meeting/在会议上; at ten o'clock/在十点钟; at (the age of) forty/在 40 岁的时候; at the beginning of the month/在月初; at Christmas/在圣诞节; aim at…/对准..; throw …at …/朝…扔…;be pleased at…/对…感到高兴;be surprised [frightened] at …/听到…而吃惊; at one's request/应某人的请求; at the rate/speed of …/以每小时..速度);
athlete: n. 运动员
Atlantic adj.大西洋的;大西洋沿岸的(the Atlantic Ocean /大西洋);
atmosphere n. 大气, 空气, 气氛;
attack n./v. 进攻, 疾病)侵袭，发作(a heart attack /心脏病发作);
attach v. 贴上，系上，缚上(attach… to … 把…贴/系在…上面)
attempt n. (常与at, on, to连用)努力, 尝试v. (常与to连用)企图, 尝试 (attempt to do sth./make an attempt to do sth. /试图做…);
attend v. 注意, 出席(at), 参加, 上(学, 教堂) ( attend school /上学; attend a lecture /听讲课; attend (at) a wedding /出席婚礼; be attended by/由...陪同; 由...照料);