【单选题】There is no denying it: Boys think differently from girls. Even though recent brain research evidence is controversial(争议的), that conclusion seems inescapable. One clue to brain differences between th...
A.
The other families might not even know a family that lived close by in the past.
B.
We live in an age of machines when machines can do everything.
C.
Neighboring is not as common as it used to be.
D.
Everyone shared the same problem—power is not enough for daily use.
【单选题】有以下四个命题: ①从1002个学生中选取一个容量为20的样本,用系统抽样的方法进行抽取时先随机剔除2人,再将余下的1000名学生分成20段进行抽取,则在整个抽样过程中,余下的1000名学生中每个学生被抽到的概率为 1 500 ; ②线性回归直线方程 ? y = ? b x+ ? a 必过点( . x , . y ); ③某厂10名工人在一小时内生产零件的个数分别是15,17,14,10,15,1...