大全866提问（考点：比较）

87338618

Tiny quantities of more than thirty rare gases, most of them industrial by-products, threaten to warm the Earth’s atmosphere even more rapidly than carbon dioxide during the next fifty years.
(A) to warm the Earth’s atmosphere even more rapidly than carbon dioxide during the next fifty years
(B) to warm the Earth’s atmosphere even more rapidly over the next fifty years than carbon dioxide will
(C) during the next fifty years to warm the Earth’s atmosphere even more rapidly than carbon dioxide
(D) a warming of the Earth’s atmosphere during the next fifty years even more rapid than carbon dioxide’s
(E) a warming of the Earth’s atmosphere even more rapid than carbon dioxide’s will be over the next fifty years
答案选B，说A因为从句carbon dioxide没有用一般将来时----during the next fifty years.
但是我认为B直接把时间状语during the next fifty years放到了主句中，首先：主句没有使用一般将来时。其次，改变句意。再次，这时的从句为什么又使用一般将来时了？？

zjhzkingsam

我认为主要是A的后半部分少了助动词，和threaten就不平行了

87338618

我看过石林的语法：他上面说谓语动词尽量补出，也可以不补出的呀~~~只要没有歧义就好了，可是我觉得这个时间状语位置改的实在让人看了很不舒服，我觉得是改了原句的意思了

zongtong

同问。其实我觉得B项补出后反而是will threaten to warm，这样的表达是很奇怪的，危险已经存在了，只是结果在未来。而且句子的意思上本来就是让rare gases和二氧化碳在同样的时间——未来的50年进行比较，这种情况下助动词是没有必要补出的，即便补出也应当与比较对象保持相同，这里就很奇怪

pennmou

想要表达的意思是Tiny quantities of ...threaten to warm the Earth’s atmosphere even more rapidly than carbon dioxide will (warm the ...)。如果没有will,我们可以理解成more rapidly than  to warm carbon dioxide，即carbon dioxide 与atmosphere并列，A项就造成歧义了。个人看法，仅供参考。

thinkingape

B: if you have a MGMAT SC guide this looks very similar to Chap 5, modifiers page 75.

The group arrived in New Orleans and decided to stay in a fancy hotel a week before Mardi Gras...

Should be written as

The group arrived in New Orleans a week before Mardi Gras and decided to stay in a fancy hotel.

The second one is correct b/c the modifier "a week before..." describes when the group arrived.

In your sentence, A the modifier "during the next fifty years" should be placed closest to what it is trying to modify.