【单选题】根据以下资料,回答20~23题。 At the first sight the planet Mars does not appear very welcome to any kind of life.It has very little oxygen and water, the temperature at night is below -50~Cand winds of 100 miles ...
A.
there is no life there now
B.
there is a large amount of water at the poles
C.
the Mars may be able to support life in the future
D.
conditions may have been similar to those on the Earth
【单选题】听力原文: If you've been on campus for very long, I'm certain that you've already heard about this course. You may know that last semester about 50 percent of the students enrolled in my course failed it....