A:A物体仅受一个弹力作用,弹力的方向垂直斜面向上
B:A物体受两个弹力作用,一个水平向左,一个垂直斜面向下
C:A物体受两个弹力作用,一个水平向右,一个垂直斜面向上
D:A物体受三个弹力作用,一个水平向右,一个垂直斜面向上,一个竖直向下
下列对名著内容的表述有错误的一项是( )
某电大女生遭多名女生抓光衣服殴打拍照上传网络,四名施暴女生以故意侮辱妇女罪分别领刑2年半至6年半不等,其中3名被告案发时还未成年,这一案例警示我们( )
设随机变量ξ的取值为0,1,2.若P(ξ=0)= 15 ,E(ξ)=1,则D(ξ)=( )
根据短文理解选择正确答案。
Here is a timetable of science activities in the Children's Palace of Xiangtan city.
Timetable
Monday
Space and Man(1 weeks)
19: 00—21: 30
Dr. Li Bin (Hunan Science and Technology University)
Would you like to know more about the outer space?
Thursday
Modern Medicine(4 weeks)
19: 00—21: 00
Dr. Zhu Jiankang (Xiangtan Central Hospital)
Would you like to know medical advances(进步)?
Tuesday
Photography(5 weeks)
18: 30—20: 30
Mr. Chen Yi, from Xiangtan Daily, will show you how to take good pictures. Please bring your own camera.
Saturday
Technical English(16 weeks)
14: 00—17: 00
Dr. Rose White Do you want to learn the technical words and articles?
Wednesday
Computer Science
18: 30—21: 00
Prof. Han Lin from Xiangtan University Learn how to use Office 2010.(3 weeks)
Sunday
Exhibition(展览)of Personal Inventions
8: 30—11: 30
You can see many inventions by the students; you may also bring your own inventions.(2 weeks)