阅读理解
For years, people have wondered whether there's life on other planets. Scientists may now be closer than ever to answering that question.
Using powerful telescopes, a team of astronomers in South America discovered a new planet, called Proxima b. It circles a star named Proxima Centauri, in the same way Earth circles the sun. Proxima Centauri is the closest star to our solar system.
Scientists believe the new planet has a rocky surface and is similar in size to Earth. More important, they've determined that the distance between Proxima b and its “sun” gives the planet a similar temperature to Earth's.This means it could have liquid water. The presence of water on a planet makes it possible for life to exist there. Scientists refer to planets like Proxima b as “Goldilocks planets” because they are not too hot or too cold, but just right to possibly support life.
Astronomers have found other Goldilocks planets in the past, but none are as close to Earth as Proxima b. Still, the new planet is 4.2 light years from Earth—that is about 25 trillion miles away.
Despite the long distance, astronomers hope to get a much better look at our new-found neighbor one day. But they'll need to wait until more advanced telescopes are developed. They may also send a robotic spacecraft to investigate the planet.
（1）Earth is to the sun what _____.
A.Proxima b is to Proxima Centauri
B.Proxima Centauri is to Proxima b
C.Proxima b is to the solar system
D.the solar system is to Proxima b
（2）The writer introduces the new planet mainly by _____.
A.listing figures
B.making the comparisons
C.following the space order
D.giving examples
（3）Planets like Proxima b are referred to as “ Goldilocks planets” because of _____.
A.their temperature
B.the presence of water
C.the life on them
D.their size
（4）We can infer from the last paragraph that _____.
A.astronomers have a long way to go to explore the new planet
B.existing telescopes are still far from advanced
C.the long distance will prevent astronomers from exploring the new planet
D.astronomers have got the whole picture of the new planet