与圆C1:x2+y2+2x﹣6y=0,C2:x2+y2﹣4x+2y+4=0都相切的直线有( )
A:1条
B:2条
C:3条
D:4条
圆柱的底面半径为1,高为2,则该圆柱体的表面积为( )
—Can you play _______ soccer?—No, I can't But I can play_______ piano.