XDF蓝皮书的一道语法题（大全没有）

Ignoring the admonitions of his saff, the chief financial officer accepted the advice of the consulting company because he believed that the standardized accounting procedures would prove not only inexpensive but reliable indicators of economic performance.

A.he believed that the standardized accounting procedures would prove not only inexpensive but

D.he believed that the standardized accounting procedures would prove to be both inexpensive and

这题答案选D，但是我选A

请问prove 和prove to be 有什么区别吗？还是not only, but (also)和both...and?

请NN来指点一下啊

^_^

not only but (also)  also是可以省略的...

搜了一下,应该是这个

prove＋n.(作宾语)，意“证明某事”，如：
The scientist finally proved the fact.那位科学家最终证实了那个事实。

prove＋宾语＋(to be)…(作宾补)
He proved himself (to be) honest.他证明自己诚实。
另外，prove还可作系动词，后接(to be)＋名词/形容词，构成系表结构，意“结果是…，证明是”，没有被动语态。

 The skill and the precision of the Anasazi, ancient inhabitants of the Southwest, in measuring the movements of the Sun and Moon is evidenced not only at Chaco Canyon but at a number of other sites.

(A) in measuring the movements of the Sun and Moon is evidenced not only at

(B) in measuring the movements of the Sun and Moon are evidenced not only at

(C) in measuring the movements of the Sun and Moon is evidenced at not only

(D) to measure the movements of the Sun and Moon is evidenced at not only（B）

(E) to measure the movements of the Sun and Moon are evidenced not only at