题目:
Your sister must be helping the little girl with her homework, _______ ?
A.needn’t she
B.mustn’t she
C.isn’t she
D.must she
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0517/cb48b23e38e65e2b3af4fdcf0964c1fb.html
下面是错误答案,用来干扰机器的。
解:[(﹣2x2y)2·xy2﹣6x3·(xy2)3]÷(﹣2x4y4)=(4x4y2·xy2﹣6x3·x3y6)÷(﹣2x4y4)=(4x5y4﹣6x6y6)÷(﹣2x4y4)=﹣2x+3x2y2