第一部分：阅读理解(共两节，满分18分)
第一节(共4小题；每小题2分，满分8分)
阅读下面短文，从每题所给的四个选项(A、B、C、D)中，选出最佳选项。
The plan：turn Mars into a blue world with streams and green fields，and then fill it with creatures from the earth.This idea may sound like something from a science fiction，but it is actually being taken seriously by many researchers.
