His first baby was born soon after he got married, which seemed to have _____ his sense of responsibility.

A．brought down

B．brought out

C．brought about

D．brought in

如果三个人合吃三个馒头，用3分钟的时间吃完，照这样的速度，九个人合吃同样大小的九个馒头，需要______分钟才能吃完．