请问og14

14. Paleontologists believe that fragments of a primate

jawbone unearthed in Burma and estimated at 40 to 44 million years old provide evidence of a crucial step along the evolutionary path that led to human beings.

(A)  at 40 to 44 million years old provide evidence of

(B)   as being 40 to 44 million years old provides evidence of

(C)  that it is 40 to 44 million years old provides evidence of what was

(D)  to be 40 to 44 million years old provide evidence of

(E)   as 40 to 44 million years old provides evidence of what was

D, the best choice, correctly follows estimated with to be. The other choices present structures that are not idiomatic when used in conjunction with estimated. Choices B, C, and E all mismatch the singular verb provides with its plural subject, fragments, and in choices C and E, what was is unnecessary and wordy. In choice C, the use of the verb phrase estimated that it is produces an ungrammatical sentence.

og说c选项动词短语有语法错误,请问是什么错误?

本人认为c的it有指代错误,这里是不能指代fragments??

这样理解对么,请指教

首先，C的这种用法很奇怪，因为这里estimated是一个过去分词作定语，加从句的这种情况几乎没有见过；

其次强调句it's 完全没有必要，what was不够简洁！

明白了,当时也是觉得estimated作定语接that从句很怪,现在更肯定了

不过be estimated at 的表达对么

estimate+that从句的用法是符合语法的。但是在这儿，还原后就不是estimate+that从句了，而是：estimate+sth.+that从句。这个合语法吗？ETS是说这个不合语法。

estimate + to do不对。应该是estimate＋noun/pronoun＋to do。to do在这个是作为宾语补足语的。

estimate＋noun/pronoun＋at也是对的。但是在这儿，还原后就变成estimate fragments at 40 to 44 million years old. 这是不对的，如果改成estimate age of fragments at 40 to 44 million years. 就对了。

不知我的理解对不对？一家之言，大家讨论讨论。

在词霸里找到一个例句:

I estimate her age at 35

支持juningw的观点

estimated 过去分词是形容词性，that引导的限定性定语从句that it is 40 to 44 million years old,只能修饰名词，不能修饰形容词。

estimated 过去分词 修饰N，本身就暗含的“被动或已完成”的意思

estimate 做主动，用estimate  sth. that..... 句型可以，其中that 从句是作为宾语的补足语。

estimate 做被动，只能是 sth. be estimated to.......