题目内容

Is there intelligent (有智力的) life on other planets? For years, scientists said “no.” or “we don’t know.” But today this is changing. Seth Shostak and Alexandra Barnett are astronomers(天文学家). They believe intelligent life exists (存在) somewhere in the universe. They also think we sill soon contact these beings(人;生物).

Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. “This is long enough for other planets to have intelligent life,” say Shostak and Barnett. The second reason is size—the universe is huge. “Tools like the Hubble Telescope(哈勃望远镜) have shown that there are at least 100 billion galaxies,” says Shostak. “And our galaxy, the Milky Way, has at least 100 billion stars. Some planets going around these stars might be similar to Earth.”

In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes allow scientists to discover smaller planets—the size of Mars or Earth—in other solar systems. These planets might have intelligent life.

Have beings from space already visited Earth? “Probably not,” says Shostak. “It’s a long way away. However, intelligent beings may contact us in other way, such as radio signals(信号). In fact, they may be trying to communicate with us now, but we don’t have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other.”

1. Seth Shostak and Alexandra Barnett are _____.

A. astronomers B. farmers C. singers D. drivers

2.What is the best title for Paragraph 2?

A. The Age and Size of Earth.

B. Our Galaxy: The Milky Way

C. Why Intelligent Life Might Exist.

D. Earth: The Only Planet with Intelligent Life

3.Why was it hard to look for signs of intelligent life in the universe in the past?

A. There were not any smaller planets.

B. There were not any powerful telescopes.

C. The astronomers were not interested in them.

D. The Milky Way didn’t exist at that time.

4. Why haven’t beings from space visited us yet according to Shostak?

A. They’re afraid of us.

B. It’s a long way away.

C. They don’t want to see us.

D. They don’t know how to use radio signals.

5.What does the underlined phrase “life forms” in the last paragraph mean?

A. Messages B. Tools

C. Intelligent beings D. Radio signals

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What would the world be like if cars could drive themselves? Imagine seeing an empty car passing by on its way to pick up its owner, or a car full of passengers who are reading, listening to music or even sleeping, but none of them are worried about the road ahead.

Well, all of this could be the future of driving. There are several companies, including Google, working on driverless (无人驾驶的) cars, which are currently in the testing stages. If the tests are successful, these electric, self-driven cars could be available very soon. But, how is it possible for a car to drive itself?

Cars already have many features allowing them to take over for drivers in certain situations. Some features include cars being able to park themselves, or slow down when they detect objects (物体) close by. They can also control the speed if there are dangerous conditions, such as snow or slippery (滑的) roads.

Other features have also changed the way drivers react to some situations. Scientists and engineers believe, with the help of wireless signals, cameras and GPS, we are now at a stage where creating a safe self-driving car might be possible.

The self-driven car may be the answer to lowering the number of deadly (致命的) accidents caused by careless drivers or dangerous conditions. However, there are still some people who do not like the idea. American lawyer Whit Drake, for example, doesn’t believe these cars are safe. He thinks the possibility of the technology making a mistake will be too high.

1.What does the underlined phrase “take over for” in Paragraph 3 mean?

A. direct the way for B. take the place of

C. work better than D. make use of

2.Cars already have the following features EXCEPT ________.

A. parking itself

B. controlling its speed in dangerous situations

C. slowing itself down near an object

D. avoiding car accidents one hundred percent

3.Scientists and engineers think that ________.

A. it’s possible to make safe self-driven cars

B. it’s a long way for self-driven cars

C. there will be no drivers in the future

D. self-driven cars may cause more accidents

4.What does the article mainly talk about?

A. Advantages of self-driven cars.

B. Different opinions on self-driven cars.

C. Possibilities of self-driven cars.

D. Google’s new technology—self-driven cars.

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