GWD 9

gmatziyu

In an effort to reduce the number of fires started by cigarettes, a major tobacco company is test-marketing a cigarette in which thin layers of extra paper are used to decrease the amount of oxygen entering the cigarette, thereby slowing the rate at which it burns and lowering the heat it generates.
A. in which thin layers of extra paper are used to decrease the amount of oxygen entering the cigarette, thereby slowing
B. in which they use thin layers of extra paper in decreasing the amount of oxygen entering the cigarette, which slows
C. that uses thin layers of extra paper to decrease the amount of oxygen when it enters the cigarette, thereby slowing
D. for which thin layers of extra paper are used to decrease the amount of oxygen that enters the cigarette, and thereby slowing
E. using thin layers of extra paper in decreasing the amount of oxygen entering the cigarette, which slows
Answer:A
请问为什么c不对呢？
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salasbond

C的错误在于，when后面的it指代不清。

fansail

不是"当oxygen进入时"减少oxygen的量，而是减少"进入的oxygen"的量。

另一个，uses thin layers of extra paper应该是人发出的而不是cigarette，但因为没有明确具体是谁发出的，用被动are used避免显示动作发出者。