跟踪导练（三）2

A

Today Ill be talking about the invention of the camera and photography. The camera is often thought to be a modern invention， but as early as 1727， a German physicist discovered that light darkens silver salt. Used as a camera， a big box was set up， and a small hole was cut in one side to let the light in； he made temporary pictures on the salt. Silver salt is still the base（基础）of the photographic film today. Then a French scientist made the first permanent picture by using a special piece of metal which was covered with silver salt. A photo graph he made in 1826 still exists.

The painter De Gear improved the process by covering the metal as well as placing the common salt which we can eat. This was in 1839， the official date of the beginning of photographs. But the problem was the printing of the photographs. And it wasnt until other scientists developed the kind of photographic paper we use now that good prints were possible and photo-graphy became truly modern. In the 1870s， Matthew Bradey was able to take his famous pictures in American Civil War. In the 1920s， Georges Mann of the United States simplified film developing（冲洗）， and Dr Edward Lane invented the so-called “Instant Camera” which uses self-developing film. If we say photography came into existence in 1839， it follows that it took more than 100 years for the camera to reach its present condition of technical refinement（密度）.

1. What discovery was the basis of photography？

A. Light darkens silver.

B. Light darkens silver salt.

C. Light darkens natural salt.

D. Light darkens self-developing film.

2. How was the first permanent picture made？

A. By making use of special paper.

B. By using a special piece of metal.

C. By adding common salt to silver salt.

D. By giving a slight colour to the silver salt.

3. Which year is regarded as the official date of the beginning of photography？

A. 1727. B. 1826.

C. 1839. D. 1870.

4. What can we learn about Matthew Bradey according to Paragraph 2？

A. He was a soldier.

B. He painted portraits.

C. He took war photographs.

D. He designed an easy-carried camera.

5. What did Doctor Edward Lane invent？

A. A new kind of film.

B. A self-action printer.

C. A cheap process of developing film at home.

D. An “Instant Camera” that develops its own film.

B

What would you think if I told you I could eat 40 percent more food than other people—eat boxes of ice cream， bowls of noodles and plates of meat—and all the while be losing weight？

You might hate me， thinking I have one of those annoyingly good metabolisms（新陈代谢）that just burn up fat when it enters my body. You might wonder if I have an eating disorder. Or maybe youd just shrug your shoulders and figure I have a rich fantasy life.

Youd be wrong.

For my body to finish such a surprising task， I would have to be a mouse. Not just any mouse， but one lucky enough to be involved in a new study at Baylor College of Medicine in Houston.

After discovering an enzyme（酶）that allows fat to be stored in the body， scientists fed mice without those enzymes， and found those mice were able to eat far more food than other mice—and still weighed 10 to 15 percent less.

Best of all， the mice without the enzyme were in very good health， were able to produce baby mice without any problem and generally acted like any other mouse. Thats great news for obesity（肥胖症）researchers， who think that scientists may figure out a way to prevent the fat-metabolizing enzyme in humans as a way to control weight gain. And such a pill would be very exciting for many struggling to get rid of dangerous extra pounds.

But dont start planning any big dinner just yet： At this point， of course， any pill for humans is but a twinkle in the eyes of every drug companys CEO. More tests are to be conducted， and eventually humans will be tested. But for now， unfortunately， controlling what you eat is still the key to losing weight.

6. What does the underlined part in Paragraph 4 refer to？

A. Controlling your diet.

B. Having a rich fantasy life.

C. Burning up fat very quickly.

D. Eating a lot of food while losing weight.

7. The study at Baylor College of Medicine ___ .

A. included both mice and humans

B. proved that mice can control their weight easily

C. proved a kind of enzyme which can cause weight gain

D. only included mice which didnt have the fat-metabolizing enzyme

8. In the study， the mice without the enzyme ___ .

A. became weak

B. acted strangely

C. were in good condition

D. could not have baby mice

9. What does the author want to tell us in the last paragraph？

A. You can be free of guilt when having big dinners.

B. Scientists cant find the key to discovering the enzyme.

C. Drug companies will make a lot of money in the future.

D. The best way for people to lose weight is still to control the diet.

10. What can be inferred from the passage？

A. The fat-metabolizing enzyme can improve metabolisms.

B. Eating a healthy diet is a good way to keep away from

disease.

C. Some drug companies have produced pills that help lose

weight.

D. The pills that help people control weight gain will be

very popular if they are available.

If you have ever been discouraged because of failure， please read on. For often， achieving what you set out to do is not the important thing. Let me explain.

Two brothers decided to dig a deep hole behind their house. As they were working， a couple of older boys stopped by to 1 . “What are you doing？” asked one of the visitors. “We plan to dig a hole all the way through the 2 ！” one of the brothers volunteered 3 .

The older boys began to 4 ， telling the younger ones that digging a hole all the way through the earth was 5 . After a long silence， one of the 6 picked up a jar full of spiders， worms and many other kinds of insects. He 7 the lid and showed the wonderful 8 to the scoffing（嘲笑的）visitors. Then he said quietly and 9 ， “Even if we dont dig all the way through the earth， look at what we have found 10

the way！”

Their 11 was far too ambitious， but it did cause them to dig. And that is what a goal is for—to cause us to move in the

12 we have chosen， in other words， to keep us 13 ！ But not every goal will be fully 14 . Not every job will end 15 . Not every hope will come to pass. Not every love will last. Not every dream will be 16 . But when you 17 short of your aim， perhaps you can say， “Yes， but look at what I found along the way！ Look at the wonderful things 18 my life because I tried to do something！” It is in the digging 19 life is lived. And I believe it is the joy in the journey that truly 20 in the end.

1. A. rest B. work C. watch D. tell

2. A. house B. earth C. wall D. road

3. A. calmly B. patiently C. excitedly D. angrily

4. A. laugh B. cry C. stare D. smile

5. A. important B. difficult C. impossible D. interesting

6. A. passers-by B. watchers C. visitors D. brothers

7. A. hit B. removed C. broke D. pushed

8. A. contents B. scenes C. pictures D. jars

9. A. properly B. confidently C. carefully D. happily

10. A. in B. along C. to D. out

11. A. goal B. toy C. name D. present

12. A. way B. direction C. life D. sight

13. A. thinking B. moving C. digging D. living

14. A. made B. prepared C. kicked D. achieved

15. A. hopelessly B. pleasantly C. surprisingly D. successfully

16. A. taken B. realized C. carried D. treasured

17. A. fall B. lose C. pay D. reach

18. A. getting into B. turning to

C. coming into D. holding to

19. A. when B. where C. which D. that

20. A. matters B. happens C. appears D. exists

用方框里单词的正确形式填空，使其句意完整，每空一词。

champion final gymnast ministry

quality score specific symbol

1. The 17-year-old little Russian girl won the hearts of everyone in the ____ hall.

2. The view set out above is based on Chinas ____ historical conditions.

3. The setting sun images ____ short and quickly passing life.

4. It is very unusual for three own goals to be ____ in one football match at international level.

5. It is reported that some ____ have as many as ten thousand staff members.

6. She reached the ____ of the 100-meter race after she made her best effort to compete with so many athletes.

7. Joe Louis has been the world heavyweight boxing ____ for many years.

8. The old lady has a ____ of kindness， so we all like her and want to help her with her housework.

下列各句均有1个错误，请改正。

1. He was late of my class over 20 minutes， which made me very angry. ____

2. More and more people join the game every year. ____

3. How cold it is， the boy always goes swimming in winter. ____

4. Can you recognize the boy in the bike is Lilys brother， who has been away from home for seven years？ ____

1. 他说谎的原因是他这次考试只得了58分。（score）

2. 如果三分之二的人同意你所说的，我们就按你说的去做。（agree with）

3. 我想知道那天在她身上究竟发生了什么事——她看起来相当难过。（on earth）

4. 那个穿粉红色运动服的黑头发女孩是谁？她很像一个我曾经认识的人。（with 复杂介词短语）

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

About three years ago， I 1 （feel） very lonely. I didnt like my classmates， my parents or anyone 2 . My classmates didnt want 3 （talk） with me and my parents were always saying that other kids were better than me. I thought I was the

4 （unlucky） person in the world.

One day I had a big fight 5 one of my classmates. I was so angry that I hit him in the face. Just at that moment， a boy stood up and stopped the fight. He was the monitor of our class.

After that， he often helped me and we became good 6

（friend）. Whenever I got angry or sad， he would help me to calm down. My life began to change because of the boy， my best friend. We spent a lot of 7 （interest） days together. As time goes by， I have become happier with people and things. And it 8 （seem） that people around me have changed， too. My parents dont shout at me any more and my classmates become friendly to me.

But now I cant see my best friend because he is 9 （serious） ill and is staying in hospital. How I miss the days 10 we were together！ I hope he will be all right and come back to school soon.

1. 2. 3. 4. 5.

6. 7. 8. 9. 10.