Five times in the earth’s history, some three-quarters of all living species disappeared forever-and within a short period of time. Those species losses stand for a major change in the planet’s ecology(生态学). Clues to these changes can be seen in the fossils(化石)and rock layers.

Today, human activities are driving species to die out at a rate never seen before. And this loss of species really does matter, said Anita Narwani. She works at the University of Michigan in Ann Arbor. That’s because the diversity(多样性)of species in an ecosystem provides people with all types of services we can’t do without.

Trees provide oxygen for us to breathe. At the same time, they remove carbon from the air which is a cause of global warming. Plants help clean air and water. Animals move seeds from one area to another. A broad range of living resources also provides people with food, shelter and medicine.

Narwani wanted to find out how important the diversity of species is for people. So she teamed up with other ecologists to review more than 1,700 studies. They found that more diverse parts of the earth tend to do well in things like removing carbon and providing us with wood and other natural resources. They were also better at keeping fisheries large and healthy so that they could feed many people.

Unfortunately, the diversity of species is in steep drop. It is too soon to say that the earth is undergoing a sixth mass extinction, Narwani said. She said a mass extinction means the loss of 75 percent of species over 2 million years or less. We haven’t lost that many – at least not yet. But according to her, if species losses continue so fast, such a mass extinction could occur in just 300 years.

The new findings highlight the potential for humans to use up many of the resources on which we now depend. As people learn more, however, they can take steps to lessen those risks. People should protect ecosystems so that they can continue to provide us with their services.

1.What’s the writer’s purpose in giving the examples in Paragraph 3?

A. To tell us how we get our food and resources.

B. To show the importance of the diversity of species.

C. To tell us the use of each species.

D. To show the writer is very learned.

2.The underlined word “They ” in Paragraph 4 refers to .

A. humans

B. Narwani and her team

C. natural resources

D. various species

3.Narwani and her team found that .

A. many people know the importance of protecting wildlife

B. many species die out because of human activities

C. making good use of natural resources benefits people

D. rich diversity of species greatly benefits people

4. We can learn from Paragraph 5 that .

A. the world’s species are dying out in a very fast rate

B. we’ll lose 75 percent of species on the earth

C. the earth is undergoing a sixth mass extinction

D. a mass extinction of species will occur in 300 years

1. I was about to go to bed _______________ suddenly, and then it spread quickly. (break )

我真准备去睡觉,突然火灾发生了并且蔓延的很快。

2._______________ in the investigation was a great shock to everybody related. ( confirm )

在调查中所被证实的事让每个相关的人都大吃一惊

3.Your words made Jane angry yesterday, so you ____________to her then. ( ought )

昨天你说的话让简很生气,你应该当时就向她道歉的。

4.By the time I graduated from junior school, my sister_______________ a famous college and we both faced a new life. ( admit )

当我初中毕业时,我姐姐已被一所著名大学录取,所以我们都面临着新的生活。

5. _______________a German plane with more than 200 people board had crashed into the Alps. ( report )

据报道一架载有200多人的德国飞机昨天坠毁在阿尔卑斯山脉里。

6. It was that picture _______________ those days when we were in the army. ( remind )

正是这张照片让我想起了我们在部队的日子。

7.This is the first time that the company _______________ the office staff. ( cut )

这是公司第一次裁减办公室职员。

8.Nowadays media can draw public attention to situations_______________. ( need )

时下,媒体能够引导公众关注一些需要帮助的情形。

9.When she first went to Australia, she often _______________ by local people because of her poor oral English. ( misunderstand )

当她第一次到澳大利亚时,她发现糟糕的英语口语常使她被当地人误解

10. Our teacher often tells us that _______________when failing in doing something means you have opportunity of success. ( win )

我们老师常说,失败中赢回自信意味着成功的可能

After the birth of my second child, I got a job at a restaurant. Having worked with an experienced for a few days. I was to wait tables on my own. All went that first week. When Saturday night came, I was luckily the tables not far from the kitchen. , I still felt it a little hard to carry the heavy trays (托盘).

Before I knew it, the was full of people. I moved slowly, every step. I remember how I was when I saw the tray stand near the tables; it looked different from the one I was on. It had nice handles, which made it to move around. I was pleased with everything and began to I was a natural at this job.

Then, an old man came to me and said, “Excuse me, dear, my wife and I loved you work. It seems your tray stand has been very to you, but we are getting ready to now, and my wife needs her back.”

At first his did not get across. “What was he talking about!” Then, I got it. I had set my trays on his wife’s orthopedic walker (助步器). I stood frozen as ice, but my face was . I wanted to get into a hole and .

Since then, I have learned from many mistakes such as the one I just . I have learned to be more and not to be too sure of myself.

1.A. manager B. assistant C. cook D. waitress

2.A. promised B. invited C. allowed D. advised

3.A. well B. quickly C. safely D. wrong

4.A. left B. given C. brought D. shown

5.A. Therefore B. However C. Otherwise D. Finally

6.A. kitchen B. street C. restaurant D. table

7.A. minding B. changing C. taking D. saving

8.A. angry B. calm C. sad D. happy

9.A. fixed B. trained C. loaded D. waited

10.A. slower B. lighter C. easier D. quieter

11.A. believe B. agree C. regret D. pretend

12.A. letting B. making C. watching D. having

13.A. useful B. familiar C. unusual D. interesting

14.A. rest B. order C. eat D. leave

15.A. bag B. walker C. tray D. coat

16.A. idea B. praise C. message D. need

17.A. cold B. full of joy C. pale D. on fire

18.A. lie B. hide C. defend D. stay

19.A. repeated B. discovered C. corrected D. described

20.A. careful B. patient C. honest D. practical

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