题型:计算题 下列因式分解中,结果正确的是( )A.x2y-y3=y(x2-y2)B.x4-4=(x2+2)(x-2)(x+2)C.x2-x-1=x(x-1-1x)D.1-(a-2)2=(a-1)(a-3) 查看答案
题型:计算题 In the past few years there _________great changes in my hometown. A.have beenB.wereC.had beenD.are 查看答案