求助一道SC

knight

According to United States Air Force official, 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.

b、shooting dead chickens at airplanes has proved itself helpful as 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

请分析此题解题思路和告知prove 用法。谢了先。

请讲一下A、E的区别。晕啊！

zhyan

E
1)shooting 应用 that shoots 来修饰,因为它不是表示一直在进行的动作
2)prove helpful in doing sth  从句意看表示在某方面有用,并非表目的

lucylu

应选E。

PROVE的用法：
prove （oneself) to be +adj.其中to be 可省略。


另：be helpful in doing sth

knight

多谢两位老大。
另傻傻地问：这里A的分词是表示一直在进行的动作还是经常性动作？偶记得分词和从句的区别是分词表示经常性动作，而从句表示具体情况。对吗？

猫猫头

从句表示一次性的动作

lucylu

分词结构不一定总表示持续的动作。
如：The train arriving at platform 8 is from Paris.
[em12]