问题 选择题

一个物体做曲线运动,则这个物体(  )

A.可能处于平衡状态

B.速度一定不断变化

C.受到的合外力方向在不断变化

D.只要受到垂直于初速度方向的恒力作用,一定做匀速圆周运动

答案

A、物体不受力或受到平衡力,物体静止或者匀速直线运动,故A错误;

B、物体做圆周运动时,速度大小可能不变,但方向一定变化,故B正确;

C、曲线运动受到的合力与速度不共线,但合力可以是恒力,如平抛运动,故C错误;

D、只要受到垂直于初速度方向的恒力作用,在初速度方向做匀速直线运动,恒力方向做匀加速直线运动,合运动是类似平抛运动,故D错误;

故选B.

阅读理解

阅读理解。

     Thank you for your interest in volunteering with the City of Melbourne's tourism program.

    If you would like to receive an email advising you of the next recruitment(招募) intake, please email

tourism@melbourne.vic.gov.au

     Information about volunteering with Tourism Melbourne

    Volunteers play a vital role in the City of Melbourne's tourism services. They provide information on

Melbourne to around two million visitors each year. Their love and knowledge of the city and regional

Victoria adds to Melbourne's reputation as a friendly, welcoming and culturally vibrant (有活力的) city.

     The City of Melbourne's tourism branch generally conducts two volunteer recruitment intakes each

year for the following tourism programs:

    City Ambassadors  

    Melbourne Visitor Booth at Bourke Street Mall  

     Melbourne Visitor Centre at Federation Square

    Melbourne Greeter Service

   Places are limited and prospective volunteers must participate in a selection process based around the

following criteria. Volunteers must be:

    第一节passionate about Melbourne

    第二节customer service focused

    第三节familiar with computer

    第四节available for one four-hour shift (either morning or afternoon) each week for a minimum of one

year

    第五节team players who love meeting with people 

    第六节able to demonstrate a commitment to the 'City of Melbournes values(as outlined in the online

application)

     More information

     To find out more about becoming a tourism volunteer, contact us online  or phone 03 9658 9658.

      For other volunteering opportunities, see national volunteer recruitment website Go Volunteer

1. Where will you most probably read the above passage? 

A. In classified tourism advertisements.

B. In a radio report of a tourism program.

C. In a book review about volunteering.

D. On a local government website.

2. Which of the following is NOT one of the requirements for a volunteer?

A. Owning a driver's license.

B. Enjoying meeting people.

C. Having computer skills.

D. A four-hour shift each week.

3. It can be inferred from the passage that ______. 

A. the program's recruitment takes place every two years

B. Go Volunteer offers more information about Melbourne's volunteer program

C. if you know Melbourne well, you are sure to be admitted as a tourism volunteer

D. even though you are interested in the program, you can't be its member right now

4. What would be the best title for the passage?

A. Does Volunteering Pay Back?

B. Welcome to the City of Melbourne!

C. Tourism Volunteer Program.

D. Interest and Tourism Volunteering.

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