统计方法中标准误一般表示
A.抽样误差
B.变异程度
C.离散程度
D.分布状况
E.可信区间
参考答案:A
Though suffering constant noise from the outside world, little Tommy was still working with all his
attention _____ on his unfinished warship model.
A.focusing
B.concentrating
C.fixed
D.looking
第一次出现骨干的IPv6Internet网络在()阶段。
A.起始
B.共存
C.主导