高三英语必修三Unit4 Astronomy：the science of the stars ——天文学：恒星科学.pptVIP

①When it is in my turn,I am too excited to speak. 当轮到我时,我激动得都说不出话来了。 ②Theory is based on practice and in turn serves practice. 理论的基础是实践,反过来理论又为实践服务。 ③You can’t all do it together;you’ll have to take turns. 你们不能全体一齐上;你们得轮流做。 ④Now it is your turn to look after the children. 现在轮到你照看孩子了。 3. prevent...from　阻止;制止 (教材P26)They are putting too much carbon dioxide into the atmosphere,which prevents heat from escaping from the earth into space.　他们把过多的二氧化碳释放到大气层中,这使得地球上的热不能释放到太空中去。 ①Once he has made up his mind,no one can prevent him from carrying out the plan. 一旦他下定决心,谁也阻止不了他执行这个计划。 ②(2012·高考安徽卷·阅读理解A)For example,there are Chinese shoes made of silk that were worn by women to tie their feet firmly to prevent them from growing too much！比如说这里有一种丝质的中国古代女子穿的鞋子,它们紧紧绑在脚上使脚不会长得太大。 ③(译林③－3)The desert was once a green land with enormous trees,but even that didn’t prevent the city from being buried by sand.那沙漠曾是巨树覆盖的绿洲,但即使那样也不能阻止整个城市被沙子埋没。 【温馨提示】 prevent/stop/keep/prohibit...from在主动语态中,keep...from中的from不能省略;在被动语态中,from都不能省略。 4. cheer up　感到高兴;感到振奋 (牛津P327)Give Mary a call; she needs cheering up. 给玛丽打个电话,她需要人安慰。 归纳拓展 (1)cheer sb.on (比赛中)以喝彩声鼓励;为某人加油 cheer the victory 为胜利而欢呼 (2)cheerful adj. 快乐的,高兴的 Cheers! (用于祝酒)干杯！ ①I do hope she can cheer up and accept the challenge of life bravely! 我真心希望她能振作起来,勇敢地接受生活的挑战！ ②They do this in order to encourage crowds to cheer their sports team on. 她们这样做是为了鼓励人们为她们的球队加油。 ③(人教⑩－1)He described it as vital for keeping us cheerful. 他把它(班卓琴)说成是保持我们精神振奋的关键。 [跟踪训练] Ⅰ.完成句子 1．______________________(使我们振奋的是) was that we floated weightlessly around in our spaceship. 2．If you don’t devote yourself to your studies,you’ll never ___________________(及时完成)． 3．We put a curtain across the window to _____________________(遮挡阳光)． 4．It was the study of history that ______________(诞生) the social sciences. What cheered us up finish them in time block out the sunlight gave birth to 5．______________(既然) most children nowadays are the only one of the family,they tend to be more self