已知复数z1=2+i,z2=1+i,则z1z2在平面内对应的点位于( )
甲、乙、丙、丁四个人各拿一个水桶到自来水龙头前等候打水.甲打水要4分钟,乙打水要1分钟,丙打水要3分钟,丁打水要2分钟.怎样安排四个人的打水顺序,才能使他们花的时间最少?( )
—There will be more and more robots going into people's homes.
— . We might be able to leave all the chores to them.