—No. In fact it is _________at the weekend.
A:How much do you charge me for it; free
B:Does it cost a lot; free of charge
C:What is the charge for it; for free
D:Could you tell me your charge for it; free
若直线2ax-by+2=0(a>0,b>0)被圆x2+y2+2x-4y+1=0截得的弦长为4,则1a+1b的最小值为( )