题目

阅读理解     Albert Einstein is right once again! He thought of the idea about gravitational waves years ago with his Theory of Relativity, but scientists are finally discovering that it really exists now. But what are gravitational waves, and why are they important?     Well, gravitational waves are made by black holes and can change time in space. Black holes aren't holes but are lots of matter put together into a very small area. They are created when a star, much like our sun, explodes and leaves behind this dense* material. It doesn't shine like a star any more, and it becomes black.     The black holes that made these waves are special. About 1.3 billion years ago, there were two black holes that kept moving closer and closer together. Finally, they hit each other and formed one big black hole. The energy is given off and created the ripples* in space. These ripples are gravitational waves. For example, imagine you throw a stone into a pool. It creates ripples that change the shape of the water. Well, that's kind of what the influence of one black hole hitting the other has in space.     Gravitational waves are hard to explore. But thanks to the efforts of scientists, the ripples were discovered on Feb. 11th, which is the first time in human history. Einstein was excellent to know this 100 years ago before we have the technology. It can give us a new view of the universe we live in. The discovery of gravitational waves, unlike stars, galaxies and other bright objects, black holes don't produce light, so we can't see them by tools. Gravitational waves allow scientists to look at the universe not only with light, but also with gravity. "Everything else in astronomy like the eye," A scientist told The New York Times. "Finally, astronomy grew ears. We had never ears before."     Now, we will be able to find black holes and things that are much further away from Earth, which means much more space exploration in the future. And who knows, this discovery could even lead to time travel! （1） Gravitational waves are ripples that are created by A . stars B . lots of matter C . different materials D . black holes （2） The third paragraph of the passage is mainly about     . A . how black holes are formed B . how gravitational waves are created C . why gravitational waves are important D . why black holes are black （3） The discovery of gravitational waves can help people         . A . understand the shape of water B . see black holes clearly C . learn more about the universe D . travel anywhere freely （4） What can we learn from the passage? A . Albert Einstein discovered gravitational waves. B . Where there are black holes, there are gravitational waves. C . Gravitational waves are to astronomy what ears to people. D . Gravitational waves are easy for scientists to be found by light. 答案： D B C C

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