大全补充250-40，没有讨论出来的问题

        Once positioned in space, the Hubble Space Telescope will capture light from sources twenty times fainter compared to those that can be detected by ground-based instruments.

(A) compared to those that can b detected

(B) compared to those they can detect

(C) than that can be detected

(D) than those that can be detected

(E) than those detecting

答案是D，those 的指代问题啊，应该是light在比吧，而非sources吧

顶起

我想了很久这道题，可是那里写的是twenty time fainter

fainter只能修饰光啊，而非resources吧。。。。

比较级后面要跟than  排除A、B 

比较的是sources     排除C 

those是被instruments detect  排除E

我的疑惑就是觉得在C D间 those 或者that 的指代上没有搞清楚，能帮我讲的更详细一点吗？

that/those在比较句中出现 可以指代前面出现过的名词的同类型的人或事  如果前面出现的是复数名词 要用those 如果是单数 就用that

比如

167. Neanderthals had a vocal tract that resembled those of the apes and so were probably without language, a shortcoming that may explain why they were supplanted by our own species.

(A)            Neanderthals had a vocal tract that resembled those of the apes

(B)            Neanderthals had a vocal tract resembling an ape's

(C)            The vocal tracts of Neanderthals resembled an ape's

(D)            The Neanderthal's vocal tracts resembled the
                apes’    （B）

(E)            The vocal tracts of the Neanderthals resembled
                those of the apes

其中A就错在用复数those指代前面的单数a vocal tract的同类事物