讨论Prep SC2 58题

58.   (27510-!-item-!-188;#058&003569)

If current trends continue, by the year 2010 carbon emissions in the United States will soar to a level more than one-third higher than were those in 1990, according to official projections.

(A) will soar to a level more than one-third higher than were those

(B) will soar to a level more than one-third higher than that

(C) would soar to a level more than one-third higher than it was

(D) would soar to a level more than one-third higher than those

(E) would soar to a level more than one-third higher than they were

答案是B

我的问题

1. 如果有条件状语从句，主句要不要用虚拟时态呢？

2. 如果上题有would soar to a level more than one-third higher than that 和will soar to a level more than one-third higher than that 选哪个答案呢？