The federal rules aimed at protecting human subjects of medical experiments were established to ensure that patients must be warned of potential risks and an independent panel would evaluate the experiment before it was conducted.
(A) must be warned of potential risks and an independent panel would
(B) must be warned of potential risks and that an independent panel
(C) are warned about potential risks and that an independent panel
(D) will be warned about potential risks and an independent panel would
(E) would be warned of potential risks and that an independent panel would
(C) are warned时态不正确，过去发生的事情应该用would(D) will be时态不正确，与后面的would也不平行；and后面缺少宾语从句引导词that。
OG12-74
In 1972 agreement between Canada and the United States reduced the amount of phosphates that municipalities had been allowed to dump into the Great Lakes.
(A) reduced the amount of phosphates that municipalities had been allowed to dump
(B) reduced the phosphate amount that municipalities had been dumping
(C) reduces the phosphate amount municipalities have been allowed to dump
(D) reduced the amount of phosphates that municipalities are allowed to dump
(E) reduces the amount of phosphates allowed for dumping by municipalities