请教全真试题第55题！

m163z

55.    According to United States Air Force officials, a cannon （shooting dead chickens at airplanes has proved helpful to demonstrate ）what kind of damage can result when jets fly into a flock of large birds.
(A) shooting dead chickens at airplanes has proved helpful to demonstrate
(B) shooting dead chickens at airplanes has proved itself helpful as a demonstration of
(C) shooting dead chickens at airplanes proves itself helpful as demonstrating
(D) that shoots dead chickens at airplanes proves itself helpful to demonstrate
(E) that shoots dead chickens at airplanes has proved helpful in demonstrating
   
   正确答案是E。在这一题的D中，我个人的理解为是应为它的时态不对而导致其错误，而并不是prove的结构用法不对！prove可以做be动词（象E中用的那样）也可以接宾语加宾补（象D中用的那样）！不知我的理解对不对？还望高人指导！
   另：A B C中shooting不对，是因为它有正在进行的意思，对于一个长期进行的情况来讲的话，因而没有that shoots好！我的理解对不对呢？
   多谢大家！！！

m163z

对不起，应为大全的55题！

mindfree

I would not use "to" as in D. Also why a canon proves itself? The meaning is wrong.

Your understanding of "v+ing" is right.

m163z

多谢总教头的指导，Also why a canon proves itself? The meaning is wrong，这个很好理解，我懂了！但不用“to”好像我还没有这个感觉，这可能与个人语感有关，看来还需努力！
多谢！！

fair_sword

正确答案是E。在这一题的D中，我个人的理解为是应为它的时态不对而导致其错误，而并不是prove的结构用法不对！

我认为与是时态没有太大的关系，是统计数据，可以用一般现在时。我觉得in更清晰，to demonstrate,可以用来表目的：例如    
The Coast Guard is conducting tests to see whether pigeons can be trained to help find survivors of wrecks at sea.
(A) to see whether pigeons can be trained to help find
(B) to see whether pigeons can be trained as help to find
(C) to see if pigeons can be trained for helping to find
(D) that see if pigeons are able to be trained in helping to find
(E) that see whether pigeons are able to be trained for help in finding

motorola00

为什么用完成时？ 没有根据啊

dreadpower

几个知识点，供参考

    PROVE习惯用法是主动表示被动
   名词+现在分词作定语，强调多次性反复性
   名词+that 从句作定语，强调一次性
   in doing ........... 在某一方面
   to 表示动作目的

Snazzy

good job, dreadpower