问题 多选题

路程和位移的关系正确的是(  )

A.运动的物体位移和路程都不可能为零

B.运动的物体在一段时间内位移可以为零,但路程不可能为零

C.运动的物体位移随时间一定越来越大

D.运动的物体路程随时间一定越来越大

答案

A、当物体运动又回到出发点时,物体的初始位置在同一个位置即物体此时的位移为0,故A错误;

B、位移由始末位置决定,可以为0;而路程为物体运动轨迹的长度,只要物体开始运动,路程就开始增加,在一个运动过程中路程不可能为0,故B正确;

C、位移由始末位置决定,在一个运动过程中远离出发点位移越来越大,靠近出发点则位移越来越小,故C错误;

D、路程是运动轨迹的长度,只要开始运动,路程就开始增加,故D正确.

故选BD.

阅读理解

A small town in southwest Britain is banning(禁止) plastic bags in an attempt to help the environment and cut waste—a step that environmentalists believe is a first for Europe.

Shopkeepers in Modbury population 1500,agreed to stop handing out disposable plastic bags to customers on Saturday.They said paper sacks and cloth carrier bags would be offered instead.

Last month,San Franciso became the first U.S. city to ban plastic grocery bags.Internationally,laws to discourage the use of plastic bags have been passed in parts of South Africa and Ireland,where governments either tax shoppers who use them or fine companies that hand them out.Bangladesh already bans them,and so do at least 30 remote Alaskan villages.

Modbury,about 225 miles southwest of London,has also declared a bag amnesty(宽限期),allowing local people to hand in plastic bags that have piled up at home.They will be sent for traveling.

The Modbury ban was the idea of Rebecca Hosking,who saw the effect of bags on marine life while working in the Pacific as a wildlife camerawoman.She said response(反应) in the town so far had been “really positive”.

“Modbury is quite an old-fashioned town and a lot of people have wicker baskets to go out shopping anyway,”Hosking told Sky News Television.

The Worldwatch Institute,an environmental research agency,states that 100 billion plastic bags are thrown away each year in the United States alone.More than 500 billion are used yearly around the world.

小题1:What was Rebecca Hosking?

A.A lawyer.

B.An environmentalist.

C.A sailor.

D.A photographer.小题2:The underlined word “disposable” in the passage probably means _______.

A.acceptable

B.valuable

C.throw-away

D.long-lasting小题3:It can be inferred from the passage that _______.

A.most of the people in Modbury continue to use plastic bags

B.fewer and fewer plastic bags will be used in the world

C.San Francisco is the first city to ban plastic bags in the world

D.most countries in the world have passed laws to ban plastic bags小题4:Which of the following would be the best title of the passage?

A.Environmental Protection

B.Big Cities Banning Plastic Bags

C.Effect of Plastic Bags on Sea Animals

D.British Town Banning Plastic Bags

单项选择题