一个初速度是3m/s,质量是5kg的运动物体,在受到方向跟初速度方向相同、大小恒

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问题:

一个初速度是3m/s,质量是5kg的运动物体,在受到方向跟初速度方向相同、大小恒为10N的合外力作用下做匀加速运动.求:

(1)物体运动的加速度大小;

(2)运动2s末物体达到的瞬时速度大小;

(3)前2s内物体运动的位移大小.

考点:匀变速直线运动的速度与时间的关系牛顿第二定律
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如图,法国大作家雨果在给朋友的信中怒斥图2所示的罪行:“在我们眼中,中国人是野蛮人,可是你看文明人对野蛮人干了些什么?”“文明人”指的是(   )

图2 焚烧后的圆明园

A.八国联军

B.英法联军

C.英美联军

D.日俄联军

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_______是学校教育中最基本的活动,它在学校整个教育系统中居于中心地位。

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简述企业持有现金的动机。

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阅读理解。

     Let's say you took violin lessons all through elementary school, but you haven't got the instrument out

of its case for years. Were all those lessons a waste of your parents' money because you didn't become a

violinist?

     Even though it has been a long time since you played the violin, a new study shows that as little as one

year of music training can have a positive impact (影响) on your brain that will last the rest of your life.

     In an experiment, researchers compared children who had taken music lessons to those who hadn't.

Laurel Trainor, who studies music and the mind, discovered that the musically-trained children had better

brain responses in certain sound recognition exams. Trainor's findings show the possibility that musical

education can actually improve the brain's hearing cortex(大脑皮层). "The study's results show that

music training affects attention and memory, and helps children develop learning skills. In this way music

training might lead to better learning across a number of fields," Trainor said in a statement. The effects

of music education are even more obvious on children with difficulty in reading and writing and other

language-related disabilities.

      So, whether you can play a good piece of music or not, it's likely that your years of music lessons

have prepared your brain for all the speeches, emails, and adult conversations that are part of your life

today. We should help make sure that children today have the same opportunities for music, and help

out by volunteering with or donating instruments to your school's music education department.

1. Compared with children who haven't taken music lessons, musically-trained children _______.

A. sing better          

B. do better in exams  

C. recognize sounds better   

D. response more quickly

2. According to the study, we know musical education can _____.

A. change the structure of the brain

B. improve children's learning skills

C. help children focus their attention

D.  provide more memorizing methods

3. What can we learn from the text?

A. Adults should also take some music lessons.

B. The author has taken violin lessons when he was young.

C. Even a day's music training can affect the human brain.

D. Music training can also help children with certain disabilities.

题型:问答题

血液透析和腹膜透析是目前治疗急性肾功能衰竭高钾血症的最有效疗法。

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