[讨论]gwd 11-28 不是反复发问！

iamduzhe

Q28:

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.

in which thin layers of extra paper are used to decrease the amount of oxygen entering the cigarette, thereby slowing

in which they use thin layers of extra paper in decreasing the amount of oxygen entering the cigarette, which slows

that uses thin layers of extra paper to decrease the amount of oxygen when it enters the cigarette, thereby slowing

for which thin layers of extra paper are used to decrease the amount of oxygen that enters the cigarette, and thereby slowing

using thin layers of extra paper in decreasing the amount of oxygen entering the cigarette, which slows

我想问一下which 前面为什么要用介词in呢?

iamduzhe

不好一次我没说清楚，答案是A，为什么又在which前加介词in

nutouch

thin layers of extra paper are user "in" the cigarette.