请教一个关于pronoun的问题

jaybumaom

第一句话：
The eyes of the elephant seal adapt to darkness more quickly than do those of any other animal yet tested, allowing it to hunt efficiently under the gloomy conditions at its feeding depth of between 300 and 700 meters.

这句话是正确的，关于这句话中的代词it，OG上的解释是“the singular pronoun it correctly agrees with its antecedent(elephant seal)” ，也就是说it是指代了elephant seal

第二句话：
Fossils of the arm of a sloth found in Puerto Rico in 1991 and dated at 34 million years old, made it the earliest known mammal of the Greater Antilles Islands.

这句话是错误的，但抛开其他错误原因，只关注代词it，OG上的错误原因是“because sloth is the object of a preposition and not the subject of the sentence, there is no reasonable antecedent for the pronoun it”

我的问题是是，“the eyes of the elephant seal”中的elephant seal和“fossils of the arm of a sloth”有什么区别，elephant seal不同样是介词短语中的object吗？并不是subject啊，为什么前者可以被拆分出来作为先行词，后者就是无法指代？

lamaqin

对于这题我也有一定困惑
但是第一句和第二句的代词位置显然不一样
第一句allowing之后属于修饰 修饰没那么严格要求代词必须和主语一致
而第二句的it是谓语之后 应该是作为宾语 所以可能位置比较严格

zfgmzjyf

说一个笨办法

The eyes of the elephant seal adapt to darkness more quickly than do those of any other animal yet tested, allowing it
看见代词，向前找指代对象，it肯定指代单数，the elephant符合

Fossils of the arm of a sloth found in Puerto Rico in 1991 and dated at 34 million years old, made it the earliest known mammal of the Greater Antilles Islands.
看见代词，向前找指代对象，it肯定指代单数，the arm符合，a sloth符合，有迷惑性，该选项持保留态度

PS：楼主应该把整道题目贴出来，sc的答案是比较出来的

eminsummer

第一句和第二句的句子结构不同，不能相比较啦。

只看主干，别的不管，
第一句是 elephant seal's eyes adapt to darkness quickly
第二句是 fossil made it the earliest mammal

这么一看，你就能看出来第二句哪里不对劲了吧？