GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - 574MI2SEKPBY4708J

The passage suggests each of the following about water on Earth EXCEPT: A. It was conveyed to Earth by comets. B. It appeared on Earth earlier than did carbon and nitrogen. C. Its existence in a liquid state is contingent on Earths orbital parameters. D. Much of it came from a part of the solar system where water cannot exist in a liquid state. E. It is unlikely that there would be much of it available to support life if the gravitational shield of the outer planets did not limit the frequency with which comets strike Earth.