back/bæk/ I. n.［c］1.(人体) 背部，(动物)脊背：If you lie on your back, you can look up at the sky. 如果你仰面躺着，你就可以看到天空。They rode up on the backs of donkeys. 他们骑到了驴背上。2.(其它东西的)背(部)，背面：the back of one’s chair 椅子的背面 The front or the back of the envelope?信封的正面还是反面? 3.后面，后部：He took a seat in the back and watched. 他在后面坐下来观看。Sit at the back of the class.坐到教室的后排去。4. 用于习语 in back of …在…后面：They sat in back of us on the plane.在机上他们坐在我们后边。turn one’s back on不卷入；拒绝帮助：Spain cannot afford to turn its back on tourism.西班牙是经不起取消旅游生意的。Surely you won’t turn your back on them?你一定不会拒绝帮助他们吗？‖II.adv. 1. 回来，回去 （与be, go, come, get以及其它动词如 bring, get, take, beat, hit, fight等连用）： I’ll be back by two.我两点前回来。Dorinda went back to her seat. 多琳达回到了她自己的位子上。 I’m coming back to England next April. 我明年四月回英国。Then I sent it back to Moore.然后我把这个东西寄回给了穆尔。Ask him to call back when he returns. 他回来时叫他回电话。 Nobody wants Richard back as president. 没有人想叫理查德再次当总统。back and forth 来回地： The chair is rocking back and forth.椅子来回摇动。2.以前：some time back 某些时候以前；as far back as 1800 远在1800年以前 ‖III. adj. (放在或位于)后面的： the back door of a house 房子的后门；a back room 后面的房间 ‖IV. vt. & vi. 1.(使)后退：The horse backed suddenly. 马突然后退了。He backed the car into (out of) the garage. 他把汽车倒进(倒出)车库。 2. 支持：I hope you will back my plan. 我希望你支持我的计划。 3.用于短语动词 back away 后退；不支持：She saw that he had a gun and backed away.她见他有枪就后退了。The government has backed away from plans to increase taxes. 政府不支持增税计划。back down/off 放弃，后退：persuade one’s opponent to back down 说服反对者放弃 Who stood firm and who backed down? 谁坚持了？谁让步了? back out退出：They backed out of the deal at the last minute. 最后一分钟他们退出了这笔交易。back up 1.倒退：You’ll have to back up and turn around. 你得往后退，然后转圈。2.支持：back a person up 支持某人，做某人的后盾