为了解1200名学生对学校教改试验的意见,打算从中抽取一个容量为30的样本,考虑采用系统抽样,则分段的间隔k为()。
A.40,
B.30,
C.20,
D.12,
参考答案:A
In 1862 the American black people won their struggle____ equal rights after many years’ fighting ________ the white.
A.against; with
B.for; against
C.with; for
D.for; for
纳税人应自领取税务登记证之日起15日内设置账簿。 ( )