问题 选择题 下列去括号错误的是( )A.a3-3(a+1)=a3-3a-3B.a3-2(a+b)=a3-2a-2bC.1-(x-y-z)=1+x+y+zD.1-(x-y+z)=1-x+y-z 答案 答案:C