My father usually____(go)to work by bus,but he____(drive)his car to work yesterday
两直线3x+y﹣3=0与6x+my+1=0平行,则它们之间的距离为( )
若A={x|x2=1},B={x|x2﹣2x﹣3=0},则A∩B=( )
按要求作图: