6. A fire in an enclosed space burns with the aid of reflected radiation that preheats the fuel, making ignition much easier and flames spreading more quickly.
(A) flames spreading
(B) flame spreads
(C) flames are caused to spread
(D) causing flames to spread
(E) causing spreading of the flames
正确答案是D,我选的E,想问问D为什么对以及E为什么错。。。谢谢啦!
自己顶一下好了。。。我选E的原因是想making ignition much easier 和causing spreading...more quickly平行,看着很工整的感觉,但是解释中说的是Choice E is wordy, unidiomatic, and also awkward in that spreading, although used here as a noun, appears at first to be another present participle that could be modified by more quickly.