问题 选择题

如图所示,A、B是两个位于固定斜面上的正方体物块,它们的质量相等,F是沿水平方向作用于A上的外力,已知A与B的接触面,A、B与斜面的接触面均光滑,下列说法正确的是                                                             (  )

A. A对B的作用力大于B对A的作用力

B.A、B可能沿斜面向下运动

C.A、B对斜面的压力相等

D.A、B受的合外力沿水平方向的分力相等

答案

BD

A对B的作用力等于B对A的作用力,A错

以整体为研究对象物体受重力支持力和水平力F可能具有沿斜面向下的合外力,则A、B可能沿斜面向下运动,B对。重力和F垂直于斜面的分力分别为,A,B对斜面的压力故A、B对斜面的压力不等,C错。因为AB具有相同的加速度所以A、B受的合外力沿水平方向的分力相等,D对

阅读理解

The artist Grandma Moses became famous for her simple, bright, cheerful paintings of American farm life.Her full name was Anna Mary Robertson Moses.But she was known to everyone as Grandma Moses because she did not begin to paint seriously until in her seventies.

Born on a farm in New York, Anna had little schooling.Her days were filled with farm chores.But she often found time to make pictures.Soon, however, she became too busy to draw or paint.At the age of 12, she went to work as a servant for a family nearby.She worked for other people for many years.Then, when she was 27, she married Thomas Moses, a farmer.And they began raising a family of their own.

Anna Moses could no longer do heavy farm work with age.Then, in her seventies, she began to paint in oils.Her pictures showed things she recalled from childhood-farm scenes, ice-skating, bringing home the Christmas tree.Later, she began to display her art at county fairs.Her pictures recorded a way of life that was quickly passing away.People everywhere loved these happy scenes, and soon her paintings were shown in art galleries.Grandma Moses became famous partially on account of her age, but mainly because her approach to art was modest and simple compared to many other painters of her time.Without formal training or even knowledge of Modernism, she relied on her own simple techniques to create her landscapes and scenes.She continued to paint almost until her death, on December 13, 1961 , at the age of 101.

The themes in her paintings provided the comfort of a rural life that many busy Americans treasured from their past.The threat of nuclear arms that appeared on television screens and in magazines had Americans starving for something more.Grandma Moses' art appealed to those who had lost hope for the future.Her classic paintings still appear on TV commercials, greeting cards, and magazine and book covers.

小题1:What can be inferred from the fact that Grandma Moses picked up a paintbrush?

A.She had no other ways to kill time.

B.Her friend and family suggested it.

C.She had had a love for painting since her childhood.

D.She needed to make a living by selling her paintings.小题2:The key reason for her success is ___  .

A.her old age

B.her plain style

C.her lack of training

D.her modern knowledge小题3:We can know from the passage that ______.

A.her paintings raised people's hope for the future

B.her paintings expressed the reality of her old age

C.many Americans were interested in purchasing art works

D.people wanted to get comfort by remembering grandmas

单项选择题 案例分析题