——The relation between the two countries gets _________. A war seems to break out soon .——I hope they will make peace with each other .
A:worse and worse
B:better and better
C:more and more peaceful
观察下列各式
(x﹣1)(x+1)=x2﹣1
(x﹣1)(x2+x+1)=x3﹣1
(x﹣1)(x3+x2+x+1)=x4﹣1
根据规律可得(x﹣1)(xn﹣1+…+x+1)=____(其中n为正整数)
—That's great. But I don't know___________ it.