大全 7 ,23；　s7,2;

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, 看过千人的解释 我想问另外一个问题.这里连个对比的事物 是不是Tiny quantities of more than thirty rare gases和carbon dioxide? 那么根据平行的法则这里不需要在carbon dioxide后面加个's么?

A study commissioned by the Department of Agriculture showed that if calves exercise and associated with other calves, they will require less medication and gain weight quicker than do those raised in confinement.

(A) associated with other calves, they will require less medication and gain weight quicker than do

(B) associated with other calves, they require less medication and gain weight quicker than

(C) associate with other calves, they required less medication and will gain weight quicker than do

(D) associate with other calves, they have required less medication and will gain weight more quickly than do（E）

(E) associate with other calves, they require less medication and gain weight more quickly than

这里Ｅ选项也有点问题：放在句子中就是...showed that if calves exercise and associate with other calves, they require less medication and gain weight more quickly than

those raised in confinement  根据句意 if句 后面的时态应该是 将来是啊 will  ?　请指点

The golden crab of the Gulf of Mexico has not been fished commercially in great numbers, primarily on account of living at great depths—2,500 to 3,000 feet down.

(A) on account of living

(B) on account of their living

(C) because it lives

(D) because of living（C）

(E) because they live

抛开错误不谈， on account ｏｆ是什么意思？　

我想你是说加s 吧

Tiny quantities of more than thirty rare gas---->复数

所以 你觉得carbon dioxide ----〉也要是复数？

比较里没有这样的规定吧 还有carbon dioxide 是countable 吗？

手头没有字典....请大家帮忙看看