1、课时作业 17.用下列情态动词完成句子1Mr White _ have arrived at 8：30 for the meeting, but he didnt turn up.2Tom, I have cleaned the room for you.Thanks. You _ not have done it. I can manage it.3He _ not have been more than 20 years old, because he just graduated from school.4He _ have finished his work, but Im not s
2、ure.5I _ have come to the party yesterday, but I had an unexpected visitor.6He _have completed his work; otherwise, he wouldnt be enjoying himself by the seaside.答案：1.should2.need3.can4.may/might5would6.must.用括号内所给动词的适当形式填空1You should _ (hand in) your composition yesterday.2The dinosaurs may _ (stop
3、) evolving already.3He may _ (come) soon; Im not sure.4There must _ (be) dinosaurs today living in other galaxies.5In the past a huge meteorite might _ (hit) all the dinosaurs.6You must _ (know) everything now.7It cant _ (be) him; he doesnt wear glasses.8If only I _ (follow) your advice.9He suggeste
4、d that the meeting should not _ (put off)答案：1.have handed in2.have stoppede4be5.have hit6.have known7.be8.had followed9.be put off.单句改错1What do you suppose has happened to him?I dont know. He should have got lost._2Jerry doesnt mind lending you his bike.He couldnt. I have borrowed Marys._3If he had
5、been here, he can have given us some help._4I didnt hear the phone. I should have been asleep._5He knew nothing about the book. He mustnt have read it before._6Liu Dong was in Jinan yesterday，so he shouldnt have come._7Did Mary come to the party?I dont know. She must have come while I was out._8He c
6、an have finished his work; otherwise, he wouldnt be enjoying music in his study._9She is two hours late. What may happen to her?_10Everyone in my class passed the exam. It mustnt have been difficult._答案：1.shouldmay/might2.couldntneednt3cancould/might/would4.shouldmust5mustntcouldnt6.shouldntcouldnt7
7、mustmay/might8.canmust9may happencan have happened10mustntcant.完形填空It was July 1976. An unmanned spaceship, Viking One, had arrived at Mars. On July 20th, the spaceship _1_. Part of it continued toward a landing on the planet. It fell _2_ through the late afternoon Mars sky.Forty kilometers above th
8、e planet, the thin _3_ began to slow its fall. Six kilometers above the planet a big parachute(降落伞) opened. The landing craft fell more slowly. Then, three rocket engines _4_. And the landing craft set down _5_ on the surface. _6_ in the Viking One Lander immediately sent a message to the earth. It
9、said, “I am here. I am down safely. I am beginning my work.”The message _7_ at the speed of light. It took twenty minutes to reach the earth, more than three hundred and twenty million kilometers _8_. Scientists and engineers at the control center _9_.Moments later, television receiver in the contro
10、l center began to _10_ the first picture from Viking One. People at the center could see the feet of the landing craft sitting firmly on the _11_ soil of Mars. Those pictures were our first _12_ look at the planet. They showed a red surface, full of rocks, with no sign of _13_. It was our first look
11、 at a planet that is full of surprises, mysteries and promise. Viking One was launched toward Mars in August, 1975. The spaceship had two _14_：an orbiter(轨道飞行器) and a lander(着陆器). The orbiter would circle _15_ Mars. It would take pictures of Mars surface. It would _16_ the atmosphere.The _17_ would
12、go down to the surface. It would carry _18_ to dig up and study soil and _19_.It also would report about any evidence of life on the planet. The lander would send this _20_ to the orbiter and then back to the earth.1A. separated B. appearedC. worked D. started2A. correctly B. slowlyC. quickly D. dir
13、ectly3A. air B. universeC. space D. atmosphere4A. fired B. fellC. opened D. floated5A. heavily B. softlyC. suddenly D. immediately6A. A computer B. A rocketC. A pilot D. An astronaut7A. spread B. traveledC. shot D. moved8A. far B. longC. distant D. away9A. shouted B. watchedC. cheered D. welcomed10A
14、. make B. takeC. show D. search11A. red B. brownC. gray D. black12A. careful B. closeC. real D. clear13A. men B. lifeC. trees D. air14A. parts B. rocketsC. engines D. centers15A. through B. towardsC. over D. around16A. enter B. examineC. collect D. discover17A. orbiter B. landerC. spaceship D. rocke
15、t18A. engineers B. astronautsC. parachutes D. instruments19A. surface B. treesC. rocks D. pictures20A. spaceship B. rocketC. lander D. information答案与解析：1A根据文章倒数第三段可知“海盗一号”宇宙飞船由orbiter和lander两部分组成，到了火星上空两部分分离。2C根据常识判断宇宙飞船应该在飞行时是很快的，在遇到阻力时才会减速，这也与后面飞行减缓后的“slowly”相对应。3Dthin可以修饰air和atmosphere，但是只有atmosp
16、here符合语境，火星的大气减慢它的飞行，而且与后文也一致。4Arocket的作用就是通过发射把lander送到火星上，着陆时需要对地面的反推力才不至于着陆太猛。5B因为前面所述的各种措施，如降落伞、火箭发动机等，所以是轻轻着陆。6A“海盗一号”是无人载飞船，所以只能通过电脑发送信息说其在工作。7B根据上下文，message以光速“传播”，spread“扩散”；shoot“发射”；move“移动”。8D表示距离时，如果有具体的数字，后面应是away。9C火星登陆成功，人们欢呼起来，shout“大喊”；watch“看”；welcome“欢迎”。10C在屏幕上show“显示”发送回来的图片，其他三
17、项意思不符。11A火星上的土壤是红色的，所以后面第二句提到红色的火星表面。12B这些照片是在火星上拍摄的，所以是close look“近看”，real不修饰look。13B根据常识可知，火星上没有生命的迹象，更没有树和人。14A宇宙飞船有两部分，由下一句话可得知答案。15Dcircle around Mars环绕火星飞行。16Bexamine指“检验”。enter“进入”，collect“收集”，discover“发现”都不合适。17B由上文可知，宇宙飞船分两部分，前面介绍了orbiter，这里介绍lander。18D在火星上，“海盗一号”只能通过一些科学仪器对火星上的土壤和岩石进行检验。19
18、C由前文中“full of rocks”可知答案。20D着陆器把在火星上得到的信息传给轨道飞行器，然后传到地球上来。.语法填空On a very cold evening, an old man was waiting for a ride across the river. He saw several horsemen pass by but he didnt ask for any help. The wait seemed _1_ (end). Then came another rider, the old man _2_(catch) his eye and said, “Sir,
19、 would you mind doing me a favor？” Stopping his horse, he replied, “Of course！” Almost, _3_ (freeze), the old man _4_ get off the ground. The horseman helped him onto his horse. He took the old man not just across the river, _5_ to his home. “Sir, you didnt even ask the other riders for help, why? W
20、hat _6_ I had said “no” and left you there？” the horseman asked. The old man looked at him straight in the eyes and said, “I looked into their eyes, I found they didnt care, _7_ told me it would be useless, but when I looked into _8_， I saw kindness”. These words touched the rider deeply. “Thank you
21、 for _9_ youve said，I hope I will never be too busy to help others.” With that, Thomas Jefferson, the _10_ (three) president of the US, turned his horse around and went away.答案与解析：1endless句中用形容词作表语。再根据上文，可确定为endless“无尽的”。2caughtcatch ones eye为固定表达，意为“引起某人的注意”；整篇文章的基本时态为一般过去时。3frozen形容词作状语，修饰主语the old man，故用frozen“冻僵了的”。4could not由上句可知不能动了。5but alsonot just.but also为并列连词，意为“不仅而且”。6if句型What if.？意为“如果将会怎样？”7whichwhich引导非限制性定语从句，修饰前面的整句话。8yours用名词性物主代词yours指代your eyes。9what。引导词在介词for后跟的宾语从句中作宾语，且表示“的事物”，故用what。10third应用序数词修饰名词president。