句子的逻辑意思：大全sec3-23

23.   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）

(E) that shoots dead chickens at airplanes has proved helpful in demonstrating

这题偶觉得逻辑意思好像变了，原文的意思应该是“大炮能射死飞机上的鸡“这件事表明what kind of ......

但是，选项e, “能射死飞机上的鸡的大炮“表明。。。。

意思不对呀？用网上经常看见的术语“改变了主从关系“，nn们给解释一下吧，谢谢

帮偶看一把呀，偶老是在逻辑意思上的题目出错。

23.   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: a cannon....helpful to demonstrate: 什么样的大炮有用...去说明....（大炮说明damage）逻辑意思不通。

hmmm, i don't think there is a logical discrepencies between A and E.

Basically, it's saying that "a connon,which can shoot dead chickens, when used at airplanes, demonstrate..."

it is helpful to do, BUT sth be helpful in ...