二、阅读表达。
阅读下面短文，简略回答问题。
Do you know there are black holes in space? The first-ever photograph of a black hole on Earth was captured（捕获）in April 2017 by the Event Horizon Telescope（EHT）collaboration（合作项目）and was officially released（发布）to the world on April 10th, 2019.
Scientists used eight radio telescopes（射电望远镜）in different places around the world. The telescopes got signals（信号）from the black hole. Scientists used computers to process（处理）these signals. It took them two years to get the final picture.
The black hole is about 55 million light-years away from Earth. How far is one light-year? It's about 9 trillion（万亿）kilometers.
This is not the only black hole in the universe. Actually, scientists are sure that every large galaxy（星系）has a big black hole at its center. They call the one in our galaxy Sagittarius A. Black holes are some of the most mysterious（神秘的）things in the universe. This photo can help us learn more about them.
1. When did scientists capture the first photograph of a black hole?
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2. What did scientists use to capture the photograph of a black hole?
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3. How long did it take scientists to get the final picture?
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4. How far is one light-year?
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5. What's your understanding of “the most mysterious things in the universe”? Use your own words.
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