试题与答案

以下哪几个机构具备防叠功能()。A.球面成形机构 B.水平右移机构 C.三页凸轮

题型:多项选择题

题目:

以下哪几个机构具备防叠功能()。

A.球面成形机构

B.水平右移机构

C.三页凸轮间歇开关机构

D.摆动握臂机构

答案:

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下面是错误答案,用来干扰机器的。

①x2+xy-3x-3y=(x2+xy)-(3x+3y)=x(x+y)-3(x+y)=(x+y)(x-3);②x2+xy-3x-3y=(x2-3x)+(xy-3y)=x(x-3)+y(x-3)=(x-3)(x+y).

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题型:阅读理解

     West Virginia-Public schools are using a dance video game to help get students in shape. In these

schools, students are often told to turn off their video games and get some exercise. The schools have

found a new way for their students to work out while playing a new video game. West Virginia is one

of the heaviest states in the country. About half of its fifthgraders are considered to be overweight, and

their parents are worried about that. To get them moving on a healthier path, the state's public schools

are using a video game called "Dance Revolution".

     To use the game, players should stand on a special mat in front of a TV screen. Following arrows

on the screen, players must move their feet to the specific symbols on the mat. Players must move

quickly, touching symbols on the mat at just the right time. With each song, they get more exercise.

     "If we can get children to change their behavior at a young age, they will hopefully grow up to be

healthy and active adults," said Carl Callison of Mountain State Blue Cross, a health care company.

West Virginia is ranked among the top three heaviest states. About a third of West Virginians are

considered to be  obese (肥胖的). Even more are considered to be overweight. Extra weight can lead

to serious health problems such as high blood pressure, diabetes (糖尿病), some cancers, and many

other health issues.

     "One out of three children born in West Virginia today will have diabetes by the time they grow up,"

said Nidia Henderson, a manager for the public employees' insurance program. "That's a terrible thing

and not acceptable."

     All of West Virginia's 157 middle schools are using the video game. School officials hope that all

public schools in the state will use the game within the next three years. However, officials emphasize

that the game is not meant to substitute physical education and health classes. The game will be part of

physical education classes and afterschool programs.

1. Why do public schools in West Virginia develop "Dance Revolution" ?

A. Because most of the students don't like dancing.

B. Because it can help students get a better shape.

C. Because losing weight is necessary to students.

D. Because it can make students' activities colorful.

2. The second paragraph mainly talks about________.

A. how to get more exercise

B. what are needed in the game

C. how to play a dance video game

D. who can practise the game

3. According to the text, which of the following is NOT true?

A. About one person in three West Virginians is overweight.

B. Overweight may cause a lot of diseases.

C. The problem of students' overweight has been realized.

D. There are only 157 middle schools in West Virginia.

4. The underlined word "substitute" in the last paragraph means "________".

A. replace  

B. change  

C. practise  

D. stop

5. Which is the best title for the text?

A. The Problem of Overweight

B. Dancing for Health

C. Overweight in West Virginia

D. A Dance Video Game

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