The gyrfalcon, an Arctic bird of prey, has survived a close brush with extinction; its numbers are now five times greater than when the use of DDT was sharply restricted in the early 1970’s.
(A) extinction; its numbers are now five times greater than
(B) extinction; its numbers are now five times more than
(C) extinction, their numbers now fivefold what they were
(D) extinction, now with fivefold the numbers they had
(E) extinction, now with numbers five times greater than
Answer:A
此题的答案解释是如果用more than 就变成是number的比较，不是gyrfalcon的比较了。个人觉得很囧，明明就是gyrfalcon ’ s number的比较嘛！！这样拆开解释我不接受。
我衍生出来的问题还有：
1，greater 和more的区别在哪里。我觉得这里都可以用。
2，为什么than后面不用补that，我觉得number are now和number（that） when这样能够平行。什么情况下才需要补that？
简单说：
对于数字的比较，我们说 这个数比那个数大，而不说这个数比那个数多
而对于具体的东西，我们说 这堆苹果比那堆苹果多 而不说这堆苹果比那堆苹果大（当然这个比较时可以的，不过意思就不对了）
英文中的搭配其实是一样的
我们说 Its numbers are greater than those numbers的意思就是 它的数字比那些数字要大，没问题
如果改成 Its numbers are more than those numbers的意思是什么呢？
是 它的数字的数量比那些数字的数量大， 换句话说比较的是numbers的数量，而不是number本身了
另外你说到的关于that的问题，实际上是一个比较从句省略的问题
我们来看看A选项
Its numbers are now five times greater than when the use of DDT was sharply restricted in the early 1970's
这句话是一个省略句，我们可以把这个句子还原成完整的句子
Its numbers are now five times greater than its numbers were when the use of DDT was sharply restricted in the early 1970's.
在上面这个句子中 it numbers 和 be动词在主句和比较从句都是完全一样的，所以可以考虑省略，并且省略之后句子不会有歧义产生，所以都可以省略了 就退化为了A选项的样子
另：LZ需要注意一下，be five time more/greater than 都不是很严谨的表达，最好应该改为 five time as great as
