Many of the successful men, had they been able to choose for themselves, would have selected some quite different professions ______ they have made fortunes.

A．from that in which

B．from which

C．in which

D．from what

可燃气体的燃烧性能常以（）来衡量。

A、火焰传播速度

B、燃烧值

C、耗氧量

D、可燃物的消耗量