题目内容

It took 100 years, but finally, scientists, from CalTech, MIT and the LIGO Scientific Collaboration, proved Albert Einstein's theory that gravitational(引力的) waves exist. The waves were predicted as part of Einstein's General Theory of Relativity nearly 100 years ago. It was the theory of the physics behind the workings of our world and the universe. The idea was that the waves are like ripples in space, caused by some of the violent and energetic processes in the Universe. For example, two black holes crashing into each other.

What are these gravitational waves? Well, imagine throwing a rock into a pond. When the rock hits the flat surface of the water, it creates ripples or waves. Space time is like the surface of the water. So that means gravitational waves are like the ripples moving out from where the rock hits the water. It might be hard to understand, but those gravitational waves expand and contract space and time as they move through space. And when they get to the Earth, the waves pass through, and contract and expand the planet as the wave goes by.

It was Einstein who said these gravitational waves should be observable. But these are not huge waves. They are very, very small, which is why it took so long to find them. You cannot see them with your eyes. They are smaller than the size of an atom.

How did the scientists find them? For years, scientists have been watching two black holes in another galaxy faraway with the help of the Laser Interferometer Gravitational-Wave Observatory. The two were spinning around each other, moving closer and closer together. When they finally crashed into each other, it was with such power and force, that gravitational waves rang throughout the universe, like a giant bell. Those waves, traveling at the speed of light, finally reached the Earth, some 1.3 billion years later. They are the same waves that the scientists announced this past week.

The National Science Foundation tweeted that each of the black holes was thought to be 29 to 36 times the mass of our sun. So, what does this discovery mean? Abhay Ashtekar, a Penn State physicist, who was not on the discovery team, said: "Our understanding of the heavens changed dramatically."

1.According to the 1st paragraph, we can learn that_______.

A. gravitational waves were part of Einstein's General Theory of Relativity

B. scientists proved that gravitational waves existed 100 years ago

C. gravitational waves were the theory of the physics behind the universe

D. gravitational waves result from two black holes crashing into each other

2.From the passage we can know that the gravitational waves______.

A. are not supposed to be observed.

B. are very huge.

C. are easy to be found.

D. can’t be seen with our eyes.

3.Why did scientists spend years watching two black holes?

A. Because they wanted to see how the two black holes crashed into each other.

B. Because they wanted to find the gravitational waves.

C. Because they wanted to see the gravitational waves reach the Earth.

D. Because they wanted to know how black holes formed.

4.What can we infer from the passage?

A. The discovery has no relation to Albert Einstein's theory

B. Throwing a rock into a pond can generate gravitational waves

C. The discovery will considerably affect people’s understanding of universe

D. gravitational waves can’t contract and expand the Earth

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Many little girls like flowers, watching butterflies and riding small horses. A lot of them also like cars, robots and spaceships. But most girls’ clothing only has pictures of flowers, butterflies or horses.

Two mothers decided to make clothes that include all the things that little girls do and love.

Six-year-old Bella loves to play with cars. So her dress has pictures of cars on it.

“We haven’t found this type of dress in the store,” Cathy, Bella’s mother, says.

The car dress is from a new girl’s clothing line called Princess Awesome. Rebecca Melsky set up the business. She says its products for girls have some designs normally found on boys’ clothes.

It all started two years ago when Rebecca was hoping to buy clothing for her two-year-old, who liked robots, trucks and spaceships.

“One day when I walked through a girls’ store, I thought to myself I wish they’d make one of those beautiful dresses that also have a robot on it because she will love that. And I thought someone should do that. Maybe I should do that,” Rebecca, said.

Her friend Eva St. Clair believed she should, and their business was born. The women sold the first 70 dresses they made at a market. So they decided to expand their business online. Their products sold very well there, too.

“They sold out so fast that I could not make them fast enough. We decided it was time to think about a factory,” Rebecca said.

So they started to raise money from people over the Internet. The women raised more than $215,000 within days, far more than the $35,000 they expected.

“Our biggest challenge is going to be how we expand as rapidly as people seem to want us to,” Rebecca said.

The women hope Princess Awesome will expand into products for girls of all ages and all interests.

1.Princess Awesome was started .

A. by Cathy and Rebecca

B. because of six-year-old Bella

C. with the help of a girls’ store

D. to make unusual clothing for girls

2.The dresses made by Rebecca and her friend .

A. sold better online than at the market

B. helped them get a job in a factory

C. were popular among girls

D. were sold expensively

3.What is the most difficult thing Rebecca and her friend will face?

A. Meeting the needs of all girls.

B. How to make interesting products.

C. Raising enough money for their business.

D. How to expand their business as people expected.

John Brown, 51, is an experienced police officer. Much of his work involves dealing with______and gang (团伙)problems in the schools of his community. Knowing that many kids often______trouble, he decided to do something about it. So in 1991 he began to invite small groups of kids to go fishing with him on his day______.

Those fun trips had a(n) ______impact. A chance encounter in 2000 proved that. One day, ______working security at a school basketball game, John noticed two young guys______. He sensed trouble between them. ______one of them headed toward John and gave him a hug. “I______you. You took me______when I was in fifth grade. That was one of the______days of my life .”

Deeply touched by the boy’s words, John decided to create a foundation(基金会)that______teenagers to the basics of fishing in camping programs. “As a policeman, I saw______there was violence, drugs were always behind it. They have a damaging______on the kids,” says John.

By turning kids on to fishing, he______to present an alternative way of life. “When you’re sitting there waiting for a______,”he says, “you can’t help but talk to each other, and such______can be pretty deep.”

“Talking about drugs helped prepare me for the peer(同龄人)pressures in high school,” says Michelle, 17, who______the first program. “And I was able to help my little brother______drugs.”

John faces______in three years, when he hopes to run the foundation full-time.“I’m living a happy life and I have a responsibility to my______to give back,” John says. “If I teach a kid to fish today, he can teach his brother to fish tomorrow.”

1.A. drugs B. drinking C. security D. smoking

2.A. left behind B. got over C. ran into D. looked into

3.A. ahead B. away C. off D. out

4.A. immediate B. damaging C. limited D. lasting

5.A. once B. since C. while D. until

6.A. quarreling B. complaining C. talking D. cheering

7.A. Slowly B. Suddenly C. Finally D. Secretly

8.A. understand B. hear C. see D. remember

9.A. swimming B. sailing C. boating D. fishing

10.A. quietest B. longest C. best D. busiest

11.A. connects B. introduces C. reduces D. commits

12.A. where B. unless C. as D. whether

13.A. impression B. burden C. decision D. impact

14.A. asked B. intended C. pretended D. agreed

15.A. solution B. change C. bite D. surprise

16.A. concerns B. interests C. conversations D. emotions

17.A. participated in B. worked out C. approved of D. made up

18.A. misuse B. Test C. tolerate D. avoid

19.A. unemployment B. challenge C. retirement D. competition

20.A. team B. school C. family D. community

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