GWD29-29，热心人看过来拉。

Q29:

Most of Portugal’s 250,000 university students boycotted classes 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.

1. year toward the cost of higher education, previously paying $7 per year
2. year toward the cost of higher education, for which was previously paid $7 per year
3. year, compared to the previously $7 per year, toward the cost of higher education
4. year toward the cost of higher education, instead of the $7 per year required previously
5. year as opposed to the $7 per year required previously for the cost of higher education

   Answer:

答案是d，我觉得选项c也说得通，compared to the previously $7 per year 作为插入语，也并没有改变原句的意思。 还请大伙指点。