Since the start of the space age, more and more littering has occurred in orbits near Earth, often because the intentional discarding of lens caps, packing material, fuel tanks, and payload covers.
(A) more and more littering has occurred in orbits near Earth, often because
(B) orbits near Earth have become more and more littered, often from
(C) orbits near Earth became littered more and more, often resulting from
(D) there have been more and more littering of orbits near Earth, often because of
(E) there had been littering more and more of orbits near Earth, often with
答案是B
可是D错在哪里？作者: allen983 时间: 2010-8-27 15:13
应该是 there be 后面不能跟抽象名词 吧