问题 选择题

下列说法正确的是(  )

A.牛顿第一定律不是实验定律,因此是不可以通过实验来验证的

B.静止在水平面上的物体对桌面的压力就是物体的重力

C.受变力作用的物体,一定做曲线运动

D.一对作用力和反作用力做功之和一定为零

答案

A、牛顿第一定律是牛顿在伽利略等前人实验的基础上,根据逻辑推理得出的,是以实验为基础,但又不是完全通过实验得出,故A正确;

B、静止在水平面上的物体对桌面的压力是由于物体恢复原状而产生的弹力,而重力则由地球的吸引产生的,故B错误;

C、受变力作用的物体,若力与运动方向共线,则做直线运动,若力与运动方向不共线则做曲线运动.故C错误;

D、一对作用力和反作用力大小相等方向相反,但它们的做功对应的位移不一定相等,所以它们做功之和不一定为零,故D错误;

故选A.

阅读理解

At the moment when looking round the world, all kinds of dance performances are being offered. There are competitions that claim to be a World Cup or World Championship, and the young dancer or the dance teacher who wants to enter his students might be quite confused. Which is which? Which is of high standard and good quality, and which is not worth going to? First of all it has clearly got to be distinguished between the different styles of dance and the purpose of such competitions. When a person wants to learn classical ballet, he or she would never dream of going to a ballroom teacher. Such a teacher might even have been world champion in his ballroom dancing, but he would definitely not be qualified in teaching proper classical ballet.

People in Britain and the USA are taking more interest in modern dance. Dance classes of all kinds are popular; the audiences going to watch modern dance companies are also larger. And perhaps the most popular modern dance company in Britain is the Ballet Rambert.

The Ballet Rambert is Britains’ oldest established dance company which began in 1926. In the 60 s the company lacked the money to go on staging big productions. The directors wanted to encourage new talent and to keep up their high standards. A change of direction was necessary. They decided to give the ballet a ‘new look” in 1966. The aim was to provide a chance for new talent – for musicians and designers as well as dancers – and to show dance as a contemporary art form. And although some of the company’s previous fans dislike the change, new audiences came to see the productions.

The modern dance pieces and modern music found unexpected popularity. In the 21 st century the Ballet Rambert was a great success in London’s West End. The company became a focus for new, progressive talent in the art.

Then, the Ballet Ramvert started to introduce young people to modern dance by giving performances at schools, which again, was a success.

The Ballet Rambert has managed to make modern dance popular while creating original and often avant – garde (标新立异) productions. It can claim to be the oldest dance company in Britain and at the same time one of the most modern!

小题1:If a person wants to learn classical ballet, he or she will go to         .

A.the Ballet Rambert

B.a ballroom teacher

C.a world champion

D.a qualified school小题2:The underlined phrase “new talent” in Para. 3 probably means         .

A.new programs

B.new audiences

C.avant – garde productions

D.skilled young dancers小题3:From the passage we know that the Ballet Rambert          .

A.has succeeded in making modern dance popular

B.wanted to become the oldest dance company

C.was once a popular dance company

D.changed old dance into new ones小题4:This passage is mainly about          .

A.the popularity of modern dance

B.the introduction to new modern dancers

C.the development of the Ballet Rambert

D.the high standard of dance performances

判断题