大全866

866.        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：B。请教下这道题为什么比较的前半部分用threaten一般现在时而比较的后半部分却用的将来时呢？请多多指教哦！

B: to warm the Earth’s atmosphere even more rapidly over the next fifty years than carbon dioxide will

1.more rapidly 是修饰warm的，所以比较的是thirty rare gases is to warm / CO2 will warm,这里是对等的。

2.threaten: 是未发生的事情，he threaten to kill you.  --->he will kill you, perhaps not.

当初我也有这样的猜想，谢谢飞鹰证实了我的想法是对的：）