一、完形填空
阅读下面短文，从短文后各题所给的四个选项（A、B、C和D)中，选出可以填入空白处的最佳选项。
Mars is not, it seems, the dry old planet we once believed __ (1) _. Astronauts who are __ (2)_ to go there in the next decade may find plenty __ (3)__ water to slake(消除) their thirst. And with water present the __ (4) _ of finding some sort of life on Mars are __ (5)__ brighter.
