请教这道大全题的考点？？谢谢

10

我不明白这题为啥要选D, B错在哪里呢？考点在哪呀

Most of Portugal’s 250000 university students boycotted classed in a one-day strike to protest a law that requires them to contribute $330 a
                year toward the cost of higher education, previously paying $7 per year.

  A.     year toward the cost of higher education, previously paying $7 per year

  B.      year toward the cost of higher education, for which was previously paid $7 per year

  C.      year, compared to the previously $7 per year, toward the cost of higher education

  D.     year toward the cost of higher education, instead of the $7 per year required previously

  E.      year as opposed to the $7 per year required previously for the cost of higher education

请楼主在标题里面给出题目出处，方便大家回帖，方便后人查询，谢谢啊

另外，多个题目，恳请一题一贴，才能方便讨论！

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GMAT机经＋MATH讨论
http://forum.chasedream.com/dispbbs.asp?boardID=22&ID=128922

GMAT语法区版规
http://forum.chasedream.com/dispbbs.asp?boardID=23&ID=79830

GMAT逻辑区格式和搜索
http://forum.chasedream.com/dispbbs.asp?boardID=24&ID=74827

GMAT阅读区-发贴格式和搜索提示
http://forum.chasedream.com/dispbbs.asp?boardID=25&ID=41017

GMAT AWA区版规
http://forum.chasedream.com/dispbbs.asp?boardID=26&ID=107312

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