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
i chose D. not sure why the answer is E. is it because you cannot use "to" (should be "in") after "helpful" ?
was struggling to choose btw D&E. i chose D in the end coz it uses "proves". "has proved" seems like gonna prove this for a period of time - I believe a cannon that shoots dead chicken proves itself helpful to demonstrate ... is better .. why it's not ?
Please help.
(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
i chose D. not sure why the answer is E. is it because you cannot use "to" (should be "in") after "helpful" ?
was struggling to choose btw D&E. i chose D in the end coz it uses "proves". "has proved" seems like gonna prove this for a period of time - I believe a cannon that shoots dead chicken proves itself helpful to demonstrate ... is better .. why it's not ?
Please help.
