1、课堂探究1Recently，however，scientists have been finding that longterm use of these fertilizers can cause damage to the land and，even more dangerous，to peoples health.然而，最近科学家发现长期使用这些肥料会造成土地受损，甚至更危险的是，会对人们的健康造成危害。剖析：1)本句的时态为现在完成进行时，其构成为：have/hasbeendoing。They have been building the bridge for two months.两
2、个月来他们一直在建桥。All the Chinese have been working hard to make our country richer and stronger.所有中国人一直都在努力工作，以使我们的国家更加富强。2)现在完成进行时和现在完成时的区别：两者都可以表示“从过去开始一直持续到现在”，但现在完成时在含义上着重表示动作的结果，不强调重复性；现在完成进行时着重表示动作的重复和动作的延续性。不能用于进行时的动词一般也不能用于现在完成进行时。如：He has finished his work and now is having a rest.他已经完成了工作，现在正在休息
3、。I have been working in this company since three years ago.自从三年前以来，我一直在这家公司工作。考点 however副词，意思是“然而”，常作插入语，可位于句首、句中或句末。如：Its raining hard.However，I think we should go to school on time.雨下得很大，但我认为该按时上学。On arriving home，however，he found his wife lying on the ground.然而，他一到家，发现妻子躺在地上。The students thought
4、they had done everything as the teacher did.They were mistaken，however.学生们认为他们按老师做的那样做了每件事，然而他们错了。单项填空1)Tom _ in the library every night over the last three months.AworksBworkedChas been working Dhad been working2)In the last few years thousands of films _ all over the world.Ahave produced Bhave bee
5、n producedCare producing Dare being produced3)Mr.Black said it was so；_，he was mistaken.Atherefore BotherwiseCbesides Dhowever答案：1)C2)B3)D2These chemicals in the food supply build up in peoples bodies over time.随着时间的推移，食物中的这些化学成分会在人体中堆积。考点 build up逐渐增强；建立；开发Many a large and big business has been bui
6、lt up from small ones.很多大企业都是从小规模发展起来的。Our country has built up her fine reputation in the world.我们的国家在世界上已逐步赢得好的声誉。He has built up a good business over the years.几年来他生意做得很兴旺。考点延伸 1)build up还可意为“积累，积聚”“变得严重起来，(车辆)拥挤起来”。如：The clouds are building up.云越聚越多。When the Spring Festival is coming，traffic bui
7、lds up along the roads.当春节到来时，路上的车辆越来越多。2)build up可用于被动结构。如：The area has been built up since I began to live here.自从我住在这儿以来，这个地区已经盖满了房子。归纳：be built up在句中表示“建筑物遍布(某地区)”。3)派生词：building n. 楼房；建筑物单项填空1) Bears _ fat stores throughout the summer and fall to have energy enough to last them through their wi
8、nter sleep.Apack upBbuild upCbring up Dtake up2)Practising Chinese kungfu can not only_ ones strength，but also develop ones character.Abring up Btake upCbuild up Dpull up完成句子3)好的食物可以增强我们的体质。Good food can _ us _.4)为了建设我们的城市，我们应该尽最大的努力工作。_ _ _ our city，we should do our best to work.答案：1)B2)C3)build；up
9、4)To build up3Many of these chemicals can lead to cancer or other illnesses.很多化学成分能导致癌症或其他疾病。考点 lead to导致；造成(后果)What on earth has led to the roads being crowded?到底是什么导致了这条公路拥挤？His carelessness led to the serious consequence.他的粗心造成了这个严重的后果。考点延伸 1)lead to除了“导致；造成(后果)”的含义外，还有其他含义。如：The road near my hou
10、se leads to Beijing.我家附近的那条路通向北京。归纳：lead to在该句的含义是：通向2)同义词：result in；cause3)lead重点短语归纳：lead by the nose牵着鼻子走lead in开始；导入lead the way带路；带头lead sb to do sth引导某人做某事lead sb to a place 引导/带领某人去某地如：Im not going to allow anyone to lead me by the nose.我不会允许任何人牵着我的鼻子走。The teacher led in the new lesson with a
11、n interesting story.那位老师用一个有趣的故事导入新课。We hired an Indian to lead the way.我们雇了一名印第安人带路。What led you to take up acting as a career?是什么使你从事演艺事业的？What led you to this conclusion?你是如何得出这个结论的？单项填空1)The discovery of new evidence led to _.Athe thief having caughtBcatch the thiefCthe thief being caughtDthe th
12、ief to be caught2) The earthquake in Japan _ the tsunami，three days after which，a baby was magically found alive while her village _ in ruins.Alead to；laid Bled to；layCaccounted for；lain Daccounted for；lied用lead短语填空3)He is the kind of person who can easily be _.答案：1)C2)B3)led by the nose4They focus
13、on keeping their soil rich and free of disease.他们主要是想保持土壤肥沃并且免受病害。考点 focus on集中(注意力、精力等)于I cant focus my attention on study with so much noise outside.外面噪音这么大，我不能把注意力集中在学习上。The discussion focused on three main problems.讨论集中在三个主要问题上。归纳：focus (sth) on中focus既可以是及物动词，也可以是不及物动词。考点延伸 1)focus on还有其他含义。如：Th
14、e astronomer focused his telescope on the moon.这位天文学家把望远镜对准月亮。Today we are going to focus on the question of homeless people in our city.今天，我们打算集中讨论我们市无家可归人群的问题。归纳：focus on在这两句中的含义分别是“对准”和“集中讨论研究”。2)focus作名词时，可作“焦点”“中心”讲。如：The focus of this chapter is the American Revolution.本章的重点是美国独立战争。She always
15、wants to be the focus of attention.她老想成为注意的中心。3)focus常用短语归纳：in focus焦点对准out of focus焦点没对准bring into focus使变得清楚；对好焦距come into focus 清晰，明确；在焦点上单项填空1)Public attention at the moment is focused_ the problems of industrial relations.AintoBtowardsCabout Don2)The report had all the attention _ traffic accid
16、ent.Afocus on Bfocusing toCfocused in Dfocused on单句改错3)He found it very difficult to focus his attention in his textbook._4)When a photograph is not in the focus，it isnt clear._答案：1)D2)D3)inon4)去掉the5A healthy soil reduces disease and helps crops grow strong and healthy.健康的土壤可以减少病害，并且帮助农作物茁壮成长。考点 re
17、duce vt.减少；缩减The price of these shoes has been reduced.这些鞋子的价格已经降了。The number of the middle school students has been reduced.中学生的数量已缩减了。考点延伸 1)反义词：increase v. 增加2)派生词：reduction n. 减少；削减；降低与reduction相关的短语：make a reduction 打折扣at a reduction of 打折扣3)reduce相关短语归纳：reduce to 降低到；落到某种境地；使(身体等)变得；化为，变成reduc
18、e by以(的比例、程度)减少Hunger reduced the young man to stealing.饥饿使这个年轻人沦落到偷窃的地步。He is reduced almost to skin and bones.他几乎变得骨瘦如柴。After careful consideration，the company decided to reduce the price by 10 percent.经过慎重考虑，该公司决定把价格降低10%。单项填空1)The organization hopes to _ poverty and hunger in developing countrie
19、s.AreduceBproduceCintroduce Dcontribute写出下列动词的名词形式2)produce _3)introduce _4)reduce _ 翻译句子5)我们需要做的事情是减少开支。_6)我可以把他的演讲简化为四个句子。_答案：1)A2)production3)introduction4)reduction5)What we need to do is to reduce expenses/costs.6)I can reduce his speech to four sentences.6This also keeps the air，soil，water and
20、 crops free from chemicals.这还可以让空气、土壤、水以及农作物不受化学物质的污染。考点 keep.free from/of使免受(影响、伤害等)；使不含(有害物)We should use new energy to keep our environment free of pollution.我们应当使用新能源，使我们的环境免受污染。Keep these vegetables free from poison.使这些蔬菜不含有毒物质。归纳：keep.free from/of中的free为形容词，在句子中作宾语补足语。考点延伸 1)free from/of意为“无的”
21、“免除的”“不受约束的”。如：They like living in a village，free from/of crowds and noises.他们喜欢住在村子里，远离人群和喧闹。She got the ticket free of charge.她免费得到了这张票。2)keep重点短语归纳：keep an eye on照看；密切注视keep away from远离；避开keep back 隐瞒；忍住(眼泪)keep company和在一起keep off(使)避开keep up with 跟上如：Please keep an eye on our baby.请照看一下我们的婴儿。We
22、 kept away from the big dog.我们远离了那只大狗。Ill keep nothing back from you.我将什么也不隐瞒你。The pet cat keeps company with him every day.那只宠物猫每天和他在一起。Keep off the grass.勿踏草坪。He does what he can to keep up with his classmates.他尽他所能跟上他的同学们。单项填空1)Eating well and exercising every day _ cold.Akeep you back fromBkeep
23、you free fromCkeep you company withDkeep you away2)This new kind of chemicals will help keep the air，soil and water_ from pollution.AfreeBemptyCloose Dshort答案：1)B2)A7They often change the kind of crop in each field every few years，for example，growing corn or wheat and then the next year peas or soyb
24、eans.他们通常每隔几年就在一块土地里换种一次农作物，比如在种玉米或小麦后的一年种豌豆或大豆。剖析：本句中的现在分词短语growing corn or wheat and then the next year peas or soybeans作伴随状语。考点 every few years 每隔几年My brother goes to the USA every few years.我的弟弟每隔几年就去一次美国。考点延伸 1)表示“每隔几”，需使用“every few复数名词”。every few metres 每隔几米every few thousand metres 每隔几千米2)eve
25、ry adj.与数词连用，意为“每，每隔”，表示时间或空间的间隔。every基数词复数名词every序数词单数名词every three hoursevery third hour 每三小时(每隔两小时)They planted a young tree every ten metres along the road.他们沿着大路每十米种一棵小树。3)表示“每隔一”，还可用“every other单数名词”表达。every other day/year 每隔一天/年every other line 每隔一行单项填空1) I saw my uncle in hospital _ and neve
26、r failed to do that.Aevery another dayBevery two dayCevery other day Devery other days2)How often do you take a bath in winter?_.AEvery two day BEvery other dayCEach other day DTwice week完成句子，每空一词3)你父母每三周来看你一次吗？Do your parents come to see you _ _ _？答案：1)C2)B3)every three weeks/every third week8.Crop
27、s such as peas or soybeans put important minerals back into the soil，making it ready for crops such as wheat or corn that need rich and fertile soil.像豌豆或大豆这样的农作物将重要的矿物质带回土壤，从而使之适宜于要求土壤肥沃的农作物，比如小麦或玉米。剖析：句中making it ready.为现在分词短语作结果状语。现在分词作结果状语，相当于一个并列谓语，描述谓语动词发生后所带来的一种自然而然的结果。Many people moved to New
28、 York，making it the largest city in the USA.很多人去了纽约，使之成为美国最大的城市。考点延伸 动词不定式也可作结果状语，但它通常表示一种“偶然的，出人意料的”结果，有时为了强调这种意外的结果，可在不定式前面加only，译为“(结果)却”“只(只是)”。He went out of the store，only to find his car gone.他走出商店，结果发现汽车被盗了。单项填空1)More highways have been built in China，_it much easier for people to travel fro
29、m one place to another.AmakingBmadeCto make Dhaving made2)The retired man donated most of his savings to the school damaged by the earthquake in Yushu，_the students to return to their classrooms.Aenabling Bhaving enabledCto enable Dto have enabled答案：1)A2)A9Swap summaries with your partner and give e
30、ach other comments.与你的搭档交换摘要，并相互作出评论。考点 comment n. 评论；议论He made no comments on our proposal.他对我们的建议没有作评论。His strange behaviour caused a great deal of comment.他怪异的行为引起了许多议论。归纳：comment既是可数名词，也是不可数名词；词组make no comments on sth的含义是“对某事不作评论”。考点延伸 comment vi.& vt.表达意见；作出评论He commented on/upon the weather.他
31、评论了一番天气。John commented that it was time for us to go home.约翰提出到我们回家的时间了。归纳：comment作不及物动词时，常和介词on，upon连用；comment作及物动词时，可接that引导的宾语从句。单项填空1)No matter who told you about the news，you shouldnt make any _，because it is none of your business.AcommentBattemptCtarget Dimpression2)The college student _ some comments on the article written by a famous writer.Amade BtookCbrought Dasked完成句子3)任何人都可以对我的工作发表意见。Anyone can _ _ my work.4)他对我的作文没有作出任何评论。He _ _ _ on my composition.答案：1)A2)A3)comment on/upon4)made no comments
