1、必修3 Unit 4 HOW LIFE BEGAN ON THE EARTHNo one knows 1._( 确切地) how the earth began, 2._ it happened so long ago. However, 3._（根据） a widely4._ (accept) theory, the universe 5._（起源于） a Big Bang that threw matter 6._（ 四面八方）. 7._（从那以后）, atoms began 8._(form ) and 9._( 结合成) create stars and other bodies.Fo
2、r several 10._（十亿） years after the Big Bang, the earth was still just11._( 一团尘埃) . 12._ it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust 13._( 慢慢地形成) a solid globe. The earth became so violent 14._ it was not clear15._ the shape would last or not. It 16._( 爆炸)
3、 loudly with fire and rock. They were 17._(及时，终于) to produce 18._（碳） , nitrogen, water vapour and other gases, 19._ were to make the earths atmosphere. What is even more important is 20._ as the earth 21._（冷却） , water began to appear on its surface. Water had also appeared on other planets like Mars
4、 but, 22._ the earth, it 23._( disappear) later. It was not24._( immediate) obvious that water was to be 25._(fundament) to the development of life. What many scientists believe is that the 26._(continue) presence of water 27._(allow) the earth to dissolve 28._(harm) gases and acids into 29._（海洋）. T
5、his produced a chain reaction, which made 30._ possible for life to develop. Many millions of years 31._（以后）, the first extremely small plants began 32._(appear) on the surface of the water. They 33._（繁殖）and filled the oceans and seas with 34._（氧气）, which 35._（鼓励） the later development of early shel
6、lfish and 36._（各种各类） fish. Next, green plants began to grow on land. They 37._( follow) in time by land animals. Some were insects. Others, 38._(call) amphibians, were able to live on land 39._（也） in the water. Later when the plants 40._（长成）forests, reptiles appeared for the first time. They produce
7、d young generally by 41._（生蛋）. After that, some huge animals, called dinosaurs, developed. They laid eggs too and 42._（生存，存在 ） on the earth for more than 140 million years. However, 65 million years ago the age of the dinosaurs ended. Why they suddenly disappeared still 43._（仍然）a mystery. This disap
8、pearance made possible the 44._（出现） of mammals on the earth. These animals were different from all life forms in the past, because they 45._（产生，分娩） young baby animals and produced milk to feed them. Finally about 2.6 million years ago some small clever animals, now with hands and feet, appeared and
9、spread all over the earth. 46._（因此）they have, 47._（接着）, become the most important animals on the planet. But they are not looking after the earth very well. They are putting too much carbon dioxide into the atmosphere, which prevents heat from48._( escape) from the earth into space. 49._（因此） , many
10、scientists believe the earth may become too hot to live on. So whether life will continue on the earth for millions of years to come will 50._（取决于）whether this problem can be solved.一. 完形填空 It surprised meevery time I saw Joe, he was smiling. It didnt1whether he had to stop at a stop light, or if he
11、 were the seventh person in2at the bank, and the service stopped just before he got there. Joe3smiled. It made me wonder why he seemed so4every day. Having observed Joe with other people, I5something else also. Joe asked people how they were doing, and really seemed to listen to their6. If someone w
12、as hurt, he had7and kind words for him and offered to8in any way he could. It made me think. . . What if I tried to smile more? A(n)9began when I went to the grocery store. I smiled as I went up and down the aisles. . . and people I didnt even10smiled back at me. Some even11! A little kid in the car
13、t(购物车)who was giving his mother a12time saw me smile and13talking. . . and, you guessed it. He made a shy little attempt at a smile. The man in the handicapped(残疾的)cart14a person to reach something. . . I could get that for him. The smile even transferred over to him, and he15me. As I drove home, I
14、was smiling. I16what I had just learned, and when someone passed me and gave me a(n)17, I smiled at him. He looked puzzled. Now I know a smile is a small thing, but what if we were all to try to smile a few more times each day? I couldnt believe how18I felt. Nothing in my life had changed, 19maybe i
15、t had. For what I learned was that such a small thing could20not only my spirits, but those around me as well. 1. A. workB. happen C. matterD. last 2. A. orderB. debt C. hand D. line 3. A. alwaysB. finally C. immediatelyD. still 4. A. naughtyB. happy C. active D. humorous 5. A. decidedB. judged C. n
16、oticedD. considered 6. A. answersB. theories C. excusesD. chains 7. A. guidance B. respect C. pityD. protection 8. A. performB. attempt C. botherD. help 9. A. experimentB. life C. projectD. program 10. A. meetB. touch C. knowD. contact 11. A. glaredB. greeted C. preventedD. escaped 12. A. spareB. lo
17、ng C. hardD. great 13. A. stoppedB. tried C. keptD. enjoyed 14. A. persuadedB. accepted C. supportedD. needed 15. A. thankedB. changed C. encouragedD. invited 16. A. worried aboutB. thought about C. talked overD. looked over 17. A. gestureB. address C. callD. ticket 18. A. normalB. great C. reasonab
18、leD. fundamental 19. A. soB. for C. butD. till 20. A. realizeB. admire C. showD. lift二.阅读理解A A special lecture began Thursday morning, given by a teacher aboard a space module about 340 kilometers above her students on the Earth, the first such attempt by Chinese. Female astronaut Wang Yaping, one o
19、f the three crew members of Shenzhou-spacecraft, greeted about 330 students at a Beijing high school, through a live video feed system. “Hello, everyone. I am Wang Yaping. I will host the lecture today, ”she said, smiling towards the camera, on board of the space module Tiangong-1. The students on h
20、er class included children from migrant(移动者, 流动者)workers families, of ethnic minorities(少数民族)and from Hong Kong, Macao and Taiwan. They are gathering at the High School affiliated to Renmin University in Beijing. More than 60 million students and teachers at about 80, 000 middle schools across the c
21、ountry are also watching the live broadcast on TV. The first section of the class was all about weight. Nie Haisheng, commander of the crew, made a bit show of crossing his legs into a meditation sitting posture in the air, which only a martial art master can do in the movies but is impossible for r
22、eal people on the Earth. “Thanks to the weightless condition, we are all masters, ”Wang joked. Then, she introduced the special scale on board of the orbiter, which was designed on basis of the Newtons second law of motion(牛顿第二运动定律), or measuring the mass of an object through the net force and the a
23、cceleration(加速度). The lesson is aimed at making space more popular, as well as inspiring enthusiasm for the universe and science, according to Zhou Jianping, designer-in-chief of Chinas manned space program, who added that the lesson will also accumulate(积累)experience for similar larger activities.
24、1. Whats the best title for the passage? A. Chinese astronaut gives the first space lectureB. Students watch Shenzhou-spacecraftC. What the conditions are like in spaceD. Ordinary people act like martial art masters 2. The lecture given in space is intended for_. A. students from BeijingB. students
25、from special areasC. students all over the countryD. students interested in space module 3. From the passage we can know that_. A. special training makes the astronauts stay in the air like martial art mastersB. astronauts are experiencing weightless conditions when in spaceC. astronauts are showing
26、 to the students how they study and live in spaceD. the Newtons second law of motion proves to be wrong in space三. 阅读填句Protecting Your EyesightNowadays most people have bad eyesight. Dont take your eyes for granted. Here are some tips on protecting your eyesight. Eat for good vision. Protecting your
27、 eyes starts with the food on your plate. Nutrients such as Vitamin C and Vitamin E may help ward off(avoid)vision problems. 1You can choose green vegetables, eggs, beans and other non-meat protein sources. Wear sunglasses for good vision. 2Choose sunglasses that block 99% to 100% of both UVA and UV
28、B rays. If you wear contact lenses, choose the ones that offer UV protection. Its still a good idea to wear sunglasses for more protection. Quit smoking. Smoking makes you more likely to get cataracts(白内障), optic nerve(视觉神经)damage, and macular degeneration(黄斑部退化). If you have tried to quit smoking b
29、efore and started smoking again, keep trying. The more times you try to quit smoking, the more likely you are to succeed. 3Staring at a computer screen can cause so many problems: dry eyes, headaches and neck, back and shoulder pain. To protect your eyes, you can position your computer so that your
30、eyes are level with the top of the monitor. This allows you to look slightly down at the screen. Try to avoid glare on your computer from windows and lights. Use an anti-glare screen if needed. Every 20 minutes, rest your eyes by looking 20 feet away for 20 seconds. 4Visit your eye doctor regularly.
31、 Everyone, even young children, should get their eyes examined regularly. 5They can also find some eye diseases, such as glaucoma(青光眼). The earlier diseases are found, the easier they are to be treated. A. Use safe eyewear. B. Look away from the computer for good eye health. C. Eye exams help you pr
32、otect your sight and see your best. D. Regularly eating nutritious foods can lead to good eye health. E. Wear glasses when examined under the guidance of your doctor. F. At least every two hours, get up and take a 15-minute break. G. The right kind of sunglasses will help protect your eyes from the suns ultraviolet(紫外线的)rays.
