[10-20 18:10:12] 来源：http://www.67xuexi.com 高二英语 阅读：85595次
* while conj. 在......的同时，当......的时候
(1) while与延续性动词连用，而when既可与延续性动词也可与终止性动词连用。
(2) 表示一个人的两个动作交替或同时进行时，多用as表示"一边......，一边......"；when很少用于这种情况。
(3) 当表示两个同步发展的情况时，多用as而不用when或while。
(4) 当表示两个短促行为或事件几乎同时发生时，用as要多于用when。
(5) while用作并列连词，连接一个并列句，意为"而，却"，表示前后意义上的对比和转折。
While he was reading，he fell asleep. 他在读书的时候睡着了。He came while we were having dinner. 我们在吃晚饭时他来了。When he came, we were having supper. 他来时，我们正吃晚饭。(不能用while) When / While I was sleeping, a thief broke in我睡觉时，小偷撬门而入。 He looked behind from time to time as he went. 他一边走，一边不时地向后看。She dances as she sings. 她一边唱歌，一边跳舞。As time went on / by, she became more and more worried. 随着时间的推移，她变得越来越烦躁不安。As children get older，they are getting more and more interested in things about them. 随着孩子们年龄的增长，他们对周围的事物越来越感兴趣。 Just as he caught the flying worm, he gave a loud cry. 他刚抓住那只飞虫，就大声地叫了起来。I thought of it just as you opened your mouth.我刚想起，你就开口说了出来。 Some people are rich while others are poor. 有些人富，有些人穷。I'm interested in sports while my brother is fond of music.我对体育很感兴趣，而我的弟弟爱好音乐。
29. They killed the bison, cut off the skins and left the bodies behind to rot. 他们把野牛杀了，剥去牛皮，抛弃尸体，任其腐烂。(p.47 Integrating Skills Reading 第四段 第4行)
★leave...behind的两种用法
▲leave...behind作"留下"解释，是执行者有意识的动作。如: ① The men had all run away leaving only old women and children. 男人们都跑了，只留下年老的妇女和孩子。② I shall leave you behind if you are not quick. 如果你不快点，我就把你丢在后面不管了。③ In their withdrawal，much of the heavy equipment had to be left behind. 他们在撤退时不得不留下许多笨重的东西。 ④ His wife left behind two little girls. 他妻子死后留下两个小女孩。⑤ You'll have to put in some extra work at night if you don't want to get left behind. 如果你不想被别人超过，就必须利用晚上时间做更多的工作。
▲leave behind还有"遗忘" "遗留"之意，为执行者无意识的动作。如: ① 0h，dear! The travelling bag has been left behind. 唉呀!旅行袋忘了拿了。② It left behind a long train of problems and difficulties.这遗留下一连串问题和困难。③ I have left my keys behind at the office. 我把钥匙忘在办公室里了。
30. With fewer bison, grass shoots were not eaten, ... 因为野牛少了，嫩草没有牛吃，... (p.47 Integrating Skills Reading 最后一段 第1行) ▲ with
(1) 表原因 My hand were blue with cold. 我的双手冻得发紫。The captain was beef-red with anger. 上尉气得满脸通红。The boy trembled with fear. 这男孩害怕得
发抖。
(2) (表示方式等)......地，......着，以...... You must handle this parcel with care. 这个包裹你须小心轻放。He speaks English with ease and fluency. 她说英语不费力而且流利。She performed the operation with great skill.她极为熟练地给病人施行手术。
(3) (表示工具，手段等)用 Did you write with a pen or pencil? 你用钢笔写还是用铅笔写? It's best to draw lines with a ruler. 用尺子划线最合适。
31. ... which as a result became less good for growing plants. 这就越来越不适合植物的生长。(p. 47 最后一段第4行)
★as a result和as a result of
▲as a result意为"因此""所以"，后面的内容表示结果，而as a result of则意为"因为(由于)......"，of后面的内容表示原因；请对照下列例句，辨析这两个词组之间的差别。① My car broke down and as a result, I was unable to get there. 我的车出了故障，因此我没能到那里去。② The flight was delayed as a result of fog. 因有雾，该航班误点。③ We went on walking in spite of the rain, as a result, we all got a bad cold. 我们不顾下雨继续往前走，结果都得了重感冒。④ He was late as a result of the traffic jam.由于交通阻塞，他迟到了。
【注】as a result后面常接一个分句，as a result of常接名词、代词或动名词。
32. ... , and the insects which lived on these plants died out. 原来靠那些植物卫生的昆虫也都死了。(p. 47 最后一段第3行)
★die out的含义
(1) (指家族, 物种)死光, 灭绝, 绝迹 These animals have already died out.这些动物已经绝种。
(2) (指习俗，做法)消失，过时 ① The old traditions are dying out. 旧传统正在消失。② That style of music died out ten years ago.那种音乐十年前就听不到了。
(3) 作熄灭解，out为副词。 The fire has died out. 火熄了。
拓展：die away 消逝，平息，静下来; die down 平息，熄灭; die for 迫切想要; die from 由于......而死; die off 一个个死掉，绝种
【注】 注意die out与die away的区别，后者主要指风、声、光等自然现象逐渐停止、消失。如: ① The wind has died away again. 风又停了。 ② The sound of the car died away in the distance. 汽车的声响在远处消逝。
上一页 [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] [63] [64] [65] [66] [67] [68] 下一页