电分段是为便于检修和缩小事故范围,将接触网分成()称为电分段。
参考答案:若干段
探索题:
(x-1)(x+1)=x2-1;
(x-1)(x2+x+1)=x3-1;
(x-1)(x3+x2+x+1)=x4-1;
(x-1)(x4+x3+x2+x+1)=x5-1
…
(1)试求:26+25+24+23+22+2+1的值;
(2)判断22014+22013+22012+22011+…+22+2+1的值的个位上是几?
the afternoon of March 8, the women in the city will have a big party. [ ]
A. To
B. In
C. At
D. On