Mars is not, it seems, the dry old planet we once believed it to be. Astronauts who are【C1】______to go there in the next decade may find plenty【C2】______water to slake(消除)their thirst.
And with water present the【C3】______of finding some sort of life on Mars are【C4】______brighter.
This is the view of 40【C5】______all over the world who have been analyzing【C6】______of pictures and other scientific【C7】______obtained by robot explorers in the sixties and seventies.
To begin with, scientists thought the Red Planet was as【C8】______as the Moon with dust storms swirling over vast sandy【C9】______. But now the picture is very different with mountains and valleys carved by【C10】______glaciers and torrential rivers rushing and rumbling deep underground.
In a report on the【C11】______of the Martian pictures Dr. Michael Car of the U.S. Geological Survey comments, "I am【C12】______there's lots of water on Mars." Any surface water will be in the【C13】______of ice. But it could【C14】______explorers having to take so much fresh【C15】______with them.
The report says【C16】______Mars probably had a warmer climate in ages【C17】______due to its axis having been more steeply tilted towards the Sun.
【C18】______convincing signs of plant or animal life have been【C19】______by instruments soft. landed on Mars,【C20】______only the immediate vicinity of landing vehicles could be examined.
【C1】

A. expected
B. hoped
C. required
D. eager