某高中共有900人，其中高一年级300人，高二年级200人，高三年级400人，现

发布时间：2017-05-03 01:41 │ 来源：www.tikuol.com

题型：选择题

问题：

某高中共有900人，其中高一年级300人，高二年级200人，高三年级400人，现采用分层抽样抽取容量为45的样本，那么高一、高二、高三各年级抽取的人数分别为（）

A．15,5,25

B．15,15,15

C．10,5,30

D．15,10,20

考点：简单随机抽样系统抽样分层抽样

题型：选择题

完形填空。

     In Australia, different people have different ways to enjoy themselves. They also have their own ideas
about  1 to pass time.
     2  children, about 80%, work hard in school because they have to take lots of exams. After school, they
don't want to stay at home reading books any more.  3 , they put aside their school bags and go out to play.
    Some old people  4 early in the morning. Then they go to park to  5 . It helps them know what is
happening around the world. In the evening, they would prefer to stay at home  6  rather than do anything
else.
    Young people enjoy having  7 trip on weekends. They go to mountains to have a picnic or go to the 8   to
camp. They usually start on Friday and spend one or two days outside. Then on   9 evening, they start their
way back home.  10  seems to be in a hurry, although a busy week is waiting for them again.

( )1. A. what
( )2. A. Some
( )3. A. However
( )4. A. get up
( )5. A. read newspapers
( )6. A. climbing hills
( )7. A. boring
( )8. A. forest
( )9. A. Friday
( )10. A. Anybody

B. how
B. Most
B. Though
B. come up
B. do sports
B. watching TV
B. busy
B. floor
B. Sunday
B. Somebody

C. when
C. All
C. Instead
C. stay up
C. enjoy themselves
C. go shopping
C. tiring
C. flat
C. Tuesday
C. Everybody

D. why
D. No
D. Or
D. set up
D. have breakfast
D. going hiking
D. relaxing
D. factory
D. Wednesday
D. Nobody

查看答案

题型：选择题

将一小球从距离地面h=0.8m的高处水平抛出，如果抛出时的速度是2m/s，那么这个小球在空中的运动时间t=______s，落地点到抛出点的水平距离s=______m（g取10m/s² ）．

查看答案

题型：选择题

实行会员分级结算制度的期货交易所会员由( )组成。

A．一级结算会员

B．二级结算会员

C．非结算会员

D．结算会员

查看答案

题型：选择题

拜新同通用名为

A．氨氯地平片
B．尼莫地平片
C．尼群地平片
D．硝苯地平控释片
E．硝苯地平片

查看答案

题型：选择题

泵入口处装密封环的作用是保护叶轮，避免与泵体摩擦和（）。

A.减小叶轮与管线之间的泄漏损失

B.减小轴与泵体之间的泄漏损失

C.减小轴与管线之间的泄漏损失

D.减小叶轮与泵体之间的泄漏损失

查看答案

更多题库