prep2007 p2一道题求解~

宋痂岛__

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

这道题我选的D，正确答案是B。时态已经明白了，但是单复数形式有些不清楚。carbon emissions不是复数形式么，为什么后面是that
希望有人帮忙解答一下~

LLEOE

这里的that指代前面的level，意思是碳排放将到达一个level，这个level比1990年碳排放的level还要高出三分之一

huuuuugo

LLEOE 发表于 2017-11-21 15:54
这里的that指代前面的level，意思是碳排放将到达一个level，这个level比1990年碳排放的level还要高出三分之 ...

我想请教下 入锅这里would改成了will 那后面的they were是不是E可以看作是carbon emissions的比较了。