题目

—Dad，can we go to the shop？I want to buy some sweets． 一__________．Can’t you see I’m busy at the moment?        A．Take it easy                                         B．No problem             C．Forget it                                             D．Don’t mention it 答案：C数a、b在数轴上的位置如图，则a2-(b+1)2=a-b-1a-b-1．