再来一题求解！

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.

1. sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of
2. sloth, that they found in Puerto Rico in 1991, has been dated at 34 million years old, thus making it the earliest mammal known on
3. sloth that was found in Puerto Rico in 1991, was dated at 34 million years old, making this the earliest known mammal of
4. sloth, found in Puerto Rico in 1991, have been dated at 34 million years old, making the sloth the earliest known mammal on
5. sloth which, found in Puerto Rico in 1991, was dated at 34 million years old, made the sloth the earliest known mammal of

答案是C 我选的的D

我感觉C错了2个地方 1: fossils 谓语动词应该用复数，2: this 指代不清楚。 请高手指教！！

大家说说 都选什么啊？？！！

d是对的，完成时表示对现在有影响的事情

c中有多处错误，首先是Fossils被发现而不是sloth，其次this指代不明，即使指代明确在gamt中也不对

a中的it也是指代不明，代词是gamt中常考的考点

該題其實所有答案都不對，選D的話，必須將 have been dated at...改為 have been dated to be...這樣就很好。

我想應該是打錯字，否則該題無解啊...

其实我也觉的该题无解的 可是这个是GWD的题目呀况且大家都做的！要是无解的话早就该有人提出来 改掉了吧！ 再等等其他高手的意见吧！ 谢谢你了

我將GWD做過一遍，有些我百思不解的題目，曾請教過我一位美國朋友，他在美國的大學任教。依他的判斷，有些題目真的錯了。但是ETS不會錯，應該是GWD當初整理時，有打錯的情形。

http://forum.chasedream.com/dispbbs.asp?BoardID=23&ID=56794

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