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 bird.
(A) shooting dead chickens at airplanes has proved helpful to demonstrate
(B) shooting dead chickens at airplanes has proved itself helpful as a demostration of
(C) shooting dead chickens at airplanes proves itself 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
我想不通A和E哪个对？觉得白勇解释的太牵强了，他用shooting 和that shoots来判断，有没有别的解释？比如是不是prove helpful to demonstrate 和prove helpful in demonstrating都可以？谢谢
作者: jnlvo 时间: 2004-3-17 00:19
prove adj. in doing,
todo错
作者: juan 时间: 2004-3-17 00:57
in demonstrating....在描述...中
