问题 填空题

以下活动中,利用惯性的有 ______,防止惯性的有 ______.(填写序号)

①用力拍打,掸去身上的灰尘;②跳远前,先助跑一定的距离;③驾驶员行车时,要系安全带;④雨雪天气,慢速行驶;⑤标枪离开手后,飞向远处;⑥鸭子抖动身体,水珠四溅.

答案

惯性在生活中有很多应用,我们利用惯性可以让物体离开力后能继续前进,如用力拍打衣服时,衣服动而灰尘由于惯性离开衣服;跳远时,助跑一段距离后,人由于惯性可以在空中继续前进;标枪离开手后,能保持速度而继续前进;鸭子抖动身体时,水珠由于惯性会离开鸭子.

同样,惯性也能给人类带来危害,如刹车时人会向前冲,雨雪天人会在路上滑倒等,故也要注意防止,如为了防止人在刹车时撞向玻璃,在行车时要系安全带;路滑时要减速行驶等.

故答案为:①②⑤⑥;③④.

阅读理解

Melissa Poe was 9 years old when she began a campaign for a cleaner environment by writing a letter to the then President Bush. Through her on efforts, her letter was reproduced on over 250 donated billboards (广告牌)across the country.

The response to her request for help was so huge that Poe established Kids For A Cleaner Environment (Kids F.A.C.E.) in 1989. There are now 300,000 members of Kids F.A.C.E. worldwide and it is the world’s largest youth environmental organization.

Poe has also asked the National Park Service to carry out a “Children’s Forest” project in every national park. In 1992, she was invited one of only six children in the world to speak at the Earth Summit in Brazil as part of the Voices of the future Program. In 1993, she was given a Caring Award for her efforts by the Caring Institute.

Since the organization started, Kids F.A.C.E. members have distributed and planted over 1 million trees! Ongoing tree-planting projects include Kids’ Yards — the creation of backyard wildlife habitats (栖息地) and now Kids F.A.C.E. is involved in the exciting Odyssey, which is a great way to start helping.

“We try to tell kids that it’s not OK to be lazy,” she explains, “You need to start being a response, environmentally friendly person now, right now, before you become a resource-sucking adult.”

72. Kids F.A.C.E. is __________.

A. a program to help students with writing

B. a project of litter recycling

C. a campaign launched by President Bush

D. a club of environmental protection

73. What can we learn about Poe?

A. She was awarded a prize in Brazil.

B. She donated billboards across the country.

C. She got positive responses for her efforts.

D. She joined the National Park Service.

74. Kid’s Yards is ____________.

A. established in national park

B. started to protect wildlife

C. a wildlife-raising project

D. an environment park for kids

75. Which of the following can be inferred from the text?

A. Adults are resources –sucking people.

B. Poe sought help from a youth organization

C. Kids F.A.C.E. members are from the U.S.

D. Kids are urged to save natural resources.

单项选择题