如图,人沿平直的河岸以速度v行走,且通过不可伸长的绳拖船,船沿绳的方向行进,此过

题型:选择题

问题:

如图,人沿平直的河岸以速度v行走,且通过不可伸长的绳拖船,船沿绳的方向行进,此过程中绳始终与水面平行.当绳与河岸的夹角为α,船的速率为(  )

A.vsinα

B.

v
sinα

C.vcosα

D.

v
cosα

考点:力的合成力的分解
题型:选择题

Ma Yan is not really a writer, but this 15-year-old girl has written a book that has moved many people around the world. Ma Yan’s diary tells us about Ma’s life. She lives in a poor village called Zhangjiashu in Tongxin, Ningxia, and she has no money to go to school. However, she is brave and wants to go to school very much.

Her mother gave her diary to a reporter, Pierre Haski when he went to Zhangjiashu in 2001. Now, Ma Yan’s diary has been published in France, Italy, Germany, Japan and China.

Ma Yan is now a Junior Three student at Yuwang Middle School in Tongxin. Before this, she had to drop out of school twice. She had to stop going to school the first time, because her mum told her there was no money for her to go to school. She worked for 21 days and saved 13 yuan. With this money, she went back to school. The second time, her family told her she had to leave school while her two brothers could stay.

“I want to study,” Ma Yan wrote in her diary. “Why can boys study but girls can’t? It would be wonderful if I could stay at school forever.”

Ma Yan loves school so much because she wants to have a better life.

“My parents work hard in the fields but they are still poor. They have no knowledge(知识). Most girls in my village leave school early and get married young. I don’t want that kind of life,” Ma Yan said.

After her story became known, many students sent money to her. She hopes to go to Tsinghua University and become a reporter. “Then, I can find poor kids like me, and help them,” she said.

小题1:Ma Yan’s diary has been published in France, Italy, Germany, Japan and       .

A.America

B.Austria

C.Russia

D.China小题2:Why did Ma Yan leave school for the first time?

A.She didn’t study as hard as her brothers.

B.Her brothers studied better than she did.

C.Her family didn’t have money for her to school.

D.She had to help her mother do some housework.小题3:Ma Yan wants to study because she wants to          .

A.teach her parents some knowledge

B.get more money for her study in university

C.become more famous in the world

D.get more knowledge to change her life

题型:选择题

在拌制石灰稳定土时,宜用1~3级的新石灰,可不经消解直接使用是()。

A.2级生石灰

B.磨细生石灰

C.块状生石灰

D.粒径大于10mm生石灰

题型:选择题

下列关于软件的叙述中,正确的是______。

A.计算机软件分为系统软件和应用软件两大类

B.Windows就是广泛使用的应用软件之一

C.所谓软件就是程序

D.软件可以随便复制使用,不用购买

题型:选择题

数据库管理员的主要任务是:()。

A.决定数据库的信息内容

B.充当数据库系统的联络员

C.决定存储结构和访问策略

D.监督系统工作

题型:选择题

由研究者控制干预措施的研究为

A.描述性研究
B.病例对照研究
C.队列研究
D.流行病学实验研究
E.分析性研究

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