题目内容：

    A new study focuses on K2-18b, an exoplanet (系外行星) like the earth discovered in 2015, orbiting a red dwarf star (矮星) close enough to receive about the same amount of radiation from its star as the earth does from the sun.

Recently, scientists have discovered gas giants that have water in their atmospheres, but this is the least massive planet ever to have water detected in its atmosphere. ''The water detection was quite clear to us relatively early on, lead author Bjorn Benneke, a professor at the Institute for Research on Exoplanets at the Universite de Montreal, '' told Space.com in an interview.

Studies have suggested that planets with hydrogen-rich atmospheres could host certain forms of life, Benneke said. However, a news release reads: ''K2-18b's large atmosphere is extremely thick and creates high-pressure conditions, which likely prevents life as we know it from existing on the planet’s surface. '' While these researchers found evidence for liquid water clouds on K2-18b because of its lack of surface, rain wouldn't pour on the planet. Without a real surface, so to speak, landing on the planet would also be nearly impossible, especially because the gas is so thick and has such an incredibly high pressure that any earthr-created space-craft sent there would be devastated.

Benneke suggests that, possibly, this planet is formed by rock absorbing large amounts of gas, like a vacuum (真空) cleaner. This absorbed gas would have more than doubled the planet and increased its volume eightfold.

To come to these conclusions, the research team analyzed the data from Hubble Space Telescope observations that they made between 2016 and 2017 of the K2-18b planet passing in front of its star eight times. It allows scientists to detect distinct characters of water in a planet's atmosphere. This team plans to expand this research even further by studying K2-18b with NASA's James Webb Space Telescope, which is set to launch in 2021. This type of research, Benneke said, is leading toward a final goal of ''being able to study the earth-like planets. '' ''We are not quite there yet. '' he said, ''but this is really exciting. ''

1.What can we learn about K2-18b?

A.It is a planet closest to the sun.

B.It hosts certain forms of life because of thick gas.

C.It is covered with thin atmosphere and liquid water.

D.It's the smallest planet with water in its atmosphere ever found.

2.What does the underlined word ''devastated'' in paragraph 3 mean?

A.Declared. B.Detected.

C.Destroyed. D.Delivered.

3.What allows scientists to detect clear characters of water in a planet's atmosphere?

A.The expansion in the research.

B.The data by the Hubble Space Telescope.

C.The goal of recognizing the real exoplanet.

D.The conclusion of increasing the planet's volume.

4.What can be the best title for the text?

A.A New Finding About K2-18b

B.NASA Helps Explore An Exoplanet

C.Humans Have Ever Landed On K2-18b

D.Scientists Determination Of Researching Space