if you play sports____a living job will sometimes be very dangerous.A.for B.at C.by D.of
问题描述：
if you play sports____a living job will sometimes be very dangerous.A.for B.at C.by D.of
应该选哪个介词呢.为什么呀.
答
If you play sports (for) a living job will sometimes be very dangerous.
如果你以某项运动为生,有时是非常危险的.