题目

You should be working instead of _________ there in bed.      A. lying           B. lie           C. lies         D. to lie 答案：A下列计算中，正确的是( )A. (2x+1)(2x﹣1)=2x2﹣1B. (x+5)(x﹣6)=x2﹣x﹣30C. (x﹣4)2=x2﹣16D. (x+2y)2=x2+2xy+4y2