What do black holes look like? We finally got the answer: they look like dark circles with a bright ring around the outside. Scientists took the world’s first photo of a black hole. The black hole is very far from Earth—about 55 million light years away. This is not the only black hole in the universe.

Black holes are mysterious in the universe. A photo can help us learn more about them. How much do you know about black holes? Try to answer the following questions.

Q: What is a black hole?

A: A black hole comes from a dying star. The star turns in to a small point. The point has much mass and strong gravity (引力) . The strong gravity of a black hole pulls things. The black hole “eats” these things. Black holes can even “eat” light. That’s why a black hole looks “black”.

Q: If black holes are “black”, how do scientists know they are there?

A: We cannot see black holes. But we can see how their strong gravity works on the things around them. A black hole’s gravity pulls dust and gas into it. And if a star is orbiting (绕轨道运行) a point in space, scientists can study the star’s orbit. They can tell if the star is orbiting a black hole.

Q: How did scientists take the picture of the black hole?

A: Scientists didn’t use a camera to take the picture. They used eight radio telescopes in different places across the world. The telescopes got information from the black hole. Scientists used computers to deal with the information. It took them two years to get the final picture.

Q: Will the sun turn into a black hole? And if it does, will it “eat” Earth?

A: The sun won’t become a black hole. According to NASA, it does not have enough mass to turn into one. When the sun dies, it will become a smaller and cooler star. Even if the sun becomes a black hole, Earth would still be safe.

【小题1】Which of the following is NOT true about black holes?

A．They are about 55 million light years away from Earth.

B．Black holes look “black” because they pull light and “eat” it.

C．There is more than one black hole in space.

【小题2】The underlined word “pulls” in the first answer most probably means ________.

A．moves

B．shakes

C．feels

【小题3】Scientists know black holes are there by ________.

A．using cameras to take pictures

B．using radio telescopes around the world

C．watching the stars carefully in the sky

【小题4】What will happen if the sun becomes a black hole?

A．Earth will die at once.

B．Earth will become black.

C．Earth will still be safe.

【小题5】The best title for the passage may be “________”.

A．Learning about black holes

B．Earth and the black holes

C．Something about the universe