[求助]2道 prep 上的题 不明白

uaniaou

1.In the Louisiana Purchase of 1803, the United States acquired 828,000 square miles for about four cents an acre, which more than doubled the country's size and that brought its western border within reach of the Pacific Ocean.

(D) The United States, in the Louisiana Purchase of 1803, for about four cents an acre, acquired 828,000 square miles, more than doubling the country's size, bringing

D项准确的是错在哪了///..?

2.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

为什么选B 呢.... -  -;

houjian517

littered表被动   since + 完成时