知识点归纳讲解(外研版必修3)

1、module 4知识点归纳讲解（外研版 必修3）Module 4 Sandstorms in Asia辅导一单元知识点归纳讲解：必修3模块4要点导读重点单词聚焦prevent, continue, mass, survive 重点短语透视be caught in, take in, give out, cut down, dig up热点语法点击动词不定式的时态和语态, but + 不定式重点单词聚焦【词条1】prevent 【课文原句】To prevent it coming nearer, the government is planting trees. (Page 32)【点拨】pre

2、vent (from) doing 此处意为“阻止做”，from可以省略。整句话意为“为了阻止沙漠的逼近，政府已经开始植树”。如： Nobody can prevent us marching forward.【拓展】类似的还有stop / keep (from) doing 。在keep from doing 中， from不能省去。因为keep doing 意为“让一直做”。如：The loud noise outside kept / prevented / stopped me from sleeping.The teacher kept me writing these words

3、one hundred times.【词条2】concerned【课文原句】I cant help but feel very concerned. （Page 36）【点拨】concerned此处意为“关心的，担心的”。后面跟about / for或者that从句。如：Im concerned that they may have got lost.She is much concerned about / for her daughters studies. 【拓展】 concern当名词讲时，意为“担心，忧虑”。搭配为 concern for / about / over sb / st

4、h或者that从句。如：She showed great concern about you. There is growing concern that they may have been killed.【词条3】mass【课文原句】Scientists have tried many ways to solve this problem and in China, a mass campaign has been started to help solve it. (Page 32)【点拨】mass 在此意为“大规模的”。另外，mass 还有“大量、大批”的意思，可构成a mass of

5、 或masses of，既可修饰可数名词，又可修饰不可数名词。整句意为“在中国，科学家们尝试用多种方法去解决这一问题，一场大规模治理沙尘暴的活动已经开始来帮助解决这一问题”。如：Before the rain, the sky had a mass of clouds. Masses of snow and rock broke away and fell on the climbers.【词条4】survive 【课文原句】You just had to hope youd survive. (Page 32)survive 此处意为“幸存，生还”，为不及物动词, 后可跟介词from或者on

6、。整句意为“你只能希望自己能够幸免”。如：Of all the people in the plane that crashed, only six survived.Many old rules have survived from times.【拓展】 survive当及物动词讲时，意为“经历（某事）而幸存”。如： Few buildings survived the sudden big earthquake. This plant may not survive the frost.【词条5】complain【课文原句】He does nothing but complain. (Pa

7、ge 36)【点拨】complain 在该句中意为“抱怨，发牢骚”，整句意思是“他什么都不做，只是抱怨”。【拓展】1. complain （to sb）about /at sth 意为“对抱怨，对发牢骚”。如：She complained to me about his rudeness.2. complain of sth 意为“诉说有病痛”。如： The patient is complaining of a serious heartache.重点短语透视【词条1】be caught in【课文原句】“To have been caught in a sandstorm was a te

8、rrible experience,” (Page 32)【点拨】be caught in 此处意为“遭遇上”。如：I was caught in the downpour on the way home from school.【拓展】catch 构成的常见短语：1. catch sb doing 偶然发觉某人做某事。如：The teacher caught him sleeping in class. 2. catch up with 赶上。如：Youll have to work harder to catch up with the top students. 【词条2】 take i

9、n, give out 【课文原句】Trees take in carbon dioxide and give out oxygen. (Page 35)【点拨1】take in 此处意为“吸收，吸入（空气、水等）”。如：Take in a deep breath. 深深吸入一口气。【拓展】take in的常见意思还有：1. take in 把拿进。 如： Please take your washing in if it rains. 2. take in 收容（留）某人住宿。如：The teacher took in several students. 【点拨2】give out 此处意为

10、“放出，散发出”, 多指气味，热量等的释放。如：The rotating machine gave out a lot of heat.【拓展】 give out的常见意思还有：1. 发（书、报）等。如：The teacher gave out the exam papers.2. 用完，耗尽。如： After five months, their food supply finally gave out. 【词条3】cut down, dig up【课文原句】 This is a process that happens when land becomes desert because of

11、 climate changes and because people cut down trees and dig up trees. (Page 32)【点拨1】cut down此处意为“砍倒”。如：They cut down many old trees and planted some young trees.【拓展】 cut down还有“消减；删减”的意思。如：Your article is too long, so please cut it down to 500 words.【点拨2】dig up此处意为“从地里挖出（某物）”。如：We dug up the tree by

12、its roots.【拓展】 dig up 还有“掘到，掘出”的意思。 如：An old vase was dug up here last month. 热点语法点击 动词不定式的时态和语态不定式的时态和语态变化表主动语态被动语态一般式to studyto be studied进行式to be studying完成式to have studiedto have been studied动词不定式的时态：判断不定式用哪种时态，就看不定式的动作和谓语动词的动作发生的先后关系。1. 一般式：一般式表示的动词，有时与谓语动词表示的动作同时发生，有时发生在谓语动词的动作之后。如：It takes on

13、ly a few hours to go to Beijing from Singapore by plane.（同时）I hope to see you again. = I hope that Ill see you again.（后来）2. 进行式： 表示动作正在进行，与谓语动词表示的动作同时发生。如：He seems to be eating something.When the boss came in, the worker pretended to be working very hard.3. 完成式：表示的动作发生在谓语动词表示的动作之前。Im sorry to have t

14、roubled you so much.(= Im sorry that I have troubled you so much.) He pretended not to have seen me before.(= He pretended that he had not seen me before) 注意： 在表示“希望、需要”等含义的动词, 如： wish, hope, expect, intend, mean, plan等的过去式之后跟不定式的完成时，表明不定式的行为并没有实现。如： We planed to have started the work at the beginni

15、ng of the month. 我们原计划在本月初开始工作。（但事实没有开始） He wished to have finished his homework last night.他原想在昨晚做完作业。（但结果没做完） but + 不定式【例句1】And yet we do nothing but talk about it.but后面跟不定式，要不要带不定式符号“to” , 取决于它前面有没有实义动词“do”(does, did)。 如果有实义动词“do”的某种形式，but后要用不带“to”的不定式，否则要用带“to”的不定式。如：She wanted nothing but to cry. (but相当于except, 表示除了以外)There was nothing to do but send for a doctor. 【例句2】I cant help but feel very concerned. cant help but do = can