精品一区二区免费在线观看_国产精品久久久久久av福利软件_97成人精品区在线播放_国内成人精品一区

精英家教網 > 初中英語 > 題目詳情

In fall 2006,the National Basketball Association (NBA)started using basketballs made with synthetic ,or man-made ,material instead of leather(皮革).They made the change be- cause they wanted every basketball they use to feel and bounce(彈起)the same.Not all leather balls are exactly alike in weight or how they bounce,but the synthetic balls are.

However,some players complained right away that the new balls bounced differently and were actually harder to control than the leather ones.

Physics helped answer questions about why the new balls felt different.For example,the scientists studied friction(摩擦力),which in this case affects the ability of a player to hold onto a ball."The greater the friction,the better it will stick to his hand,"explains a scientist.

Tests on both wet and dry balls showed that while the synthetic ball was easier to hold onto when dry,it had less friction and became much harder to hold onto when wet.That's because sweat(汗水) stays on the surface of the synthetic balls but gets taken into the leather balls.

The scientists also tested bounce and found that the logo (商標)printed on the new balls made their surface uneven(不平) and caused them to bounce a little strangely com- pared with the leather balls.

In January,the NBA went back to using the leather bails.They aren't perfect,but for now,that's just the way the ball bounces.

1.Why were the synthetic balls expected to be used in NBA according to the text?

       A.Because they are easier to control.           B.Because they waste less material.

       C.Because they look exactly alike.             D.Because they feel and bounce alike.

2.The ball is easier to hold on to_________

A.when friction is greater                    B.when friction is less

C.when it is heavier                         D.when it bounces strangely

3.The synthetic ball bounces differently from the leather one mainly because _________

A.it is wet                                  B.it is dry

C.there's a logo on it                       D.its weight remains the same

4.It can be inferred(推斷) from the text that _________.

A.a synthetic ball takes in water faster than a leather ball

B.a leather ball is more difficult to make than a synthetic one

C.a synthetic ball is more expensive than a leather ball

D.a leather ball may increase its weight during a game

5.The underlined word" They" in the last paragraph refers to __________.

A.the synthetic balls                        B.the leather balls

C.the ball players                          D.the scientists

練習冊系列答案
相關習題

科目:初中英語 來源:2012屆江蘇揚州中學教育集團初三第一次模擬考試英語試卷(帶解析) 題型:完型填空

Last fall I put a bird feeder outside my window. I thought as soon as I hung up, a great ___16____ beautiful birds would come. Days, weeks and months went by; ____17____, no birds.
I asked many people, why? What was I doing ___18____? “Nothing,” most of them replied. “Just ____19____.” So I waited, waited and waited.
I ____20____ off the deck (露臺), I changed the feed, I ___21____ the feeders, and I ____22____ made the cat go out the other door! But ____23___ seemed to work. So --- I waited, “with patience and hope. ”
Two months later, early in the morning, I was ____24____. A beautiful bird had been on the bird feeder. All of a sudden, I saw hundreds upon hundreds of birds____25____ from everywhere.
____26____ a beautiful lesson this living thing taught me! “Patience and hope” will ____27____ the most beautiful things in life.
So I keep hoping and waiting, waiting and ___28____. I will try to use this “little lesson” in ____29____ many other things in my life. I guess, “____30____ is a virtue (美德)” after all.

【小題1】
A.littleB.manyC.muchD.lot
【小題2】
A.soB.becauseC.howeverD.and
【小題3】
A.badB.wrongC.wellD.good
【小題4】
A.goB.sitC.watchD.wait
【小題5】
A.wentB.putC.cleanedD.took
【小題6】
A.boughtB.soldC.washedD.took
【小題7】
A.alwaysB.hardlyC.evenD.sometimes
【小題8】
A.nothingB.everythingC.somethingD.anything
【小題9】
A.sadB.surprisedC.worriedD.frightened
【小題10】
A.comingB.goingC.leavingD.singing
【小題11】
A.ThatB.WhichC.HowD.What
【小題12】
A.spendB.takeC.bringD.come
【小題13】
A.hopingB.dreamingC.watchingD.asking
【小題14】
A.soB.suchC.muchD.very
【小題15】
A.dreamB.patienceC.volunteeringD.lesson

查看答案和解析>>

科目:初中英語 來源:2013屆重慶市西南大學附屬中學九年級6月(第九次)月考英語試卷(帶解析) 題型:完型填空

完型填空。(每小題2分,共20分)
根據短文內容,從A、B、C、D四個選項中選出一個能填入相應空格內的最佳答案。
Every year thousands of people get hurt or die when they are crossing the road. Most of these people are old people and children. Old people often get hurt or die because  1  can’t see or hear very well. Children usually meet with accidents because they are   2 . They forget to look around   3  they cross the road.
How can we lessen (減少) traffic accidents? All of us must   4  the traffic rules. For the drivers, they shouldn’t drive too fast. If they drive too fast, it will be very difficult to stop the  5 in a very short time. For the pedestrians(行人),it’s very important to be careful while they are   6  on the road. Therefore, when we walk   7  the road, we must try to walk along the pavements(人行道). We must stop and look   8  ways before crossing the road. Look left first, next look right, and then look left again. Only when we are sure that the road is clear, we can cross it. The right way to cross the road is to walk   9 . It’s not safe to walk too slowly or run fast. If people run across the road, they may   10 . As teenagers, we should try to help children, old people or blind people to cross the road. The last one is that we should never play in the street.

【小題1】
A.weB.theyC.heD.them
【小題2】
A.happyB.youngC.carelessD.sad
【小題3】
A.afterB.beforeC.althoughD.if
【小題4】
A.obeyB.makeC.breakD.set
【小題5】
A.oldB.youngC.carD.train
【小題6】
A.walkingB.drivingC.cleaningD.standing
【小題7】
A.throughB.overC.acrossD.off
【小題8】
A.allB.bothC.eitherD.neither
【小題9】
A.quicklyB.slowlyC.happilyD.safely
【小題10】
A.fall behindB.fall downC.lie downD.set off

查看答案和解析>>

科目:初中英語 來源:2013-2014學年浙江省溫州地區九年級上學期第一次月考英語試卷(解析版) 題型:其他題

五位病人想去醫院看病。請閱讀右欄A—F六位專科醫生的簡介,根據五位病人的健康問題為他們選出最合適的專科醫生診病,并將對應字母寫在序號邊上。(有一項為多余選項)

1.Kent has lots of work to do every day. He can’t fall asleep at night.

2.8-year-old Dongdong has a sweet tooth. He has already had four bad teeth.

3.Linlin’s father just can’t give up drinking.

4.Betty is putting on weight but can’t stop eating.

5.Nina has a high fever because of the flu. She has such a big headache that she can’t go to school.  A. Dr. Yang is good at helping people give up drinking.

B. Dr. Smith has different kinds of false teeth for people who are over 20.

C. Dr. Li is good at treating flu (fever, cough etc.)

D. Dr. Chen has a lot of experience in helping patients get enough sleep.

E. Dr. Wright is always ready to offer help on eating problems.

F. Dr. Liu has great skills in fixing bad teeth and communicating with kids to win their trust.

 

查看答案和解析>>

科目:初中英語 來源:2013-2014學年北京市石景山區九年級上學期期末考試英語試卷(解析版) 題型:閱讀理解

Carmen Arace Middle School is situated in the pastoral town of Bloomfield, Conn., but four years ago it faced many of the same problems as inner-city schools in nearby Hartford: low scores on standardized tests and dropping enrollment(入學注冊). Then the school’s hard-driving headmaster, Delores Bolton, persuaded her board to shake up the place by buying a laptop computer for each student and teacher to use, in school and at home. What’s more, the board provided wireless Internet access at school. Total cost: $2.5 million.

Now, an hour before classes start, every seat in the library is taken by students who cannot wait for getting online. Fifth-grade teacher Jen Friday talks about different kinds of birds as students view them at a colorful website. After school, students on buses pull laptops from backpacks to get started on homework. Since the computer arrived, enrollment is up 20%. Scores on state tests are up 35%.

Indeed, school systems in rural Maine and New York City also hope to follow Arace Middle School’s example. Governor Angus King had planned using $50 million to buy a laptop for all of Maine’s 17,000 seventh-graders – and for new seventh-graders each fall.

In the same spirit, the New York City board of education voted on April 12 to create a school Internet portal(入口), which would make money by selling ads and licensing public school students. Profits(盈利)will also provide e-mail service for the city’s 1.1 million public school students. Profits will be used to buy laptops for each of the school system’s 87,000 fourth-graders. Within nine years, all students in grades 4 and higher will have their own computers.

Back in Bloomfield, in the meantime, most of the kinks have been worked out. Some students were using their computers to visit unauthorized(非法的)websites. But teachers have the ability to keep an eye on where students have been on the Web and to stop them. “That is the worst when they disable you,” says eighth-grade honors student Jamie Bassell. The habit is rubbing off on parents. “I taught my mom to use e-mail,” says another eighth-grader, Katherine Hypolite. “And now she’s taking computer classes. I’m so proud of her!”

1.The example of Carmen Arace Middle School in the passage is used to ______.

A. show the problems schools are faced with today

B. prove that a school without high enrollment can do well

C. express the importance of computers in modern education

D. tell that laptops can help improve students’ school performance

2.According to the writer, students in New York City’s public schools will ______.

A. enjoy e-mail service in the near future

B. make money by selling ads on websites

C. all have their own laptops within nine years

D. become more interested in their studies with laptops

3.The underlined word “kinks” in the last paragraph most probably means ______.

A. plans         B. projects       C. problems      D. products

4.From the passage we learn that ______.

A. a school Internet portal is the key to a laptop program

B. the laptop program also has a good influence on parents

C. students slowly accept the fact their online activities controlled

D. the laptop program in public school is mainly for the eighth-graders

 

查看答案和解析>>

科目:初中英語 來源:2011-2012學年江蘇揚州中學教育集團初三第一次模擬考試英語試卷(解析版) 題型:完型填空

Last fall I put a bird feeder outside my window. I thought as soon as I hung up, a great ___16____ beautiful birds would come. Days, weeks and months went by; ____17____, no birds.

   I asked many people, why? What was I doing ___18____? “Nothing,” most of them replied. “Just ____19____.” So I waited, waited and waited.

   I ____20____ off the deck (露臺), I changed the feed, I ___21____ the feeders, and I ____22____ made the cat go out the other door! But ____23___ seemed to work. So --- I waited, “with patience and hope. ”

   Two months later, early in the morning, I was ____24____. A beautiful bird had been on the bird feeder. All of a sudden, I saw hundreds upon hundreds of birds____25____ from everywhere.

   ____26____ a beautiful lesson this living thing taught me! “Patience and hope” will ____27____ the most beautiful things in life.

So I keep hoping and waiting, waiting and ___28____. I will try to use this “little lesson” in ____29____ many other things in my life. I guess, “____30____ is a virtue (美德)” after all.

1.A. little       B. many         C. much        D. lot

2.A. so           B. because      C. however     D. and

3.A. bad          B. wrong        C. well        D. good

4.A. go           B. sit          C. watch       D. wait

5.A. went         B. put          C. cleaned     D. took

6.A. bought       B. sold         C. washed      D. took

7.A. always       B. hardly       C. even        D. sometimes

8.A. nothing    B. everything   C. something   D. anything

9.A. sad    B. surprised          C. worried     D. frightened

10.A. coming  B. going        C. leaving     D. singing

11.A. That        B. Which        C. How         D. What

12.A. spend       B. take         C. bring       D. come

13.A. hoping      B. dreaming    C. watching   D. asking

14.A. so          B. such         C. much        D. very

15.A. dream       B. patience     C. volunteering  D. lesson

 

查看答案和解析>>

同步練習冊答案
精品一区二区免费在线观看_国产精品久久久久久av福利软件_97成人精品区在线播放_国内成人精品一区
福利电影一区二区| 久久综合色8888| 日韩av中文在线观看| 日韩三级在线免费观看| 久久国产视频网| 久久久久国色av免费看影院| 国产精品一区二区在线播放| 国产精品视频观看| 色综合中文综合网| 亚洲一区二区三区中文字幕 | 欧美一区二区三区视频免费| 美国av一区二区| 久久精子c满五个校花| 不卡欧美aaaaa| 亚洲一区二区高清| 日韩欧美一级二级三级久久久| 国产一区欧美二区| 中文字幕一区二区不卡| 欧美三日本三级三级在线播放| 日本亚洲欧美天堂免费| 久久久久久久综合狠狠综合| 99久久精品国产精品久久| 亚洲成a人片综合在线| 精品国产凹凸成av人网站| 成人免费的视频| 亚洲国产精品久久久男人的天堂| 日韩一区二区免费在线观看| 国产成人免费视| 亚洲一区二区av电影| 精品捆绑美女sm三区| 9l国产精品久久久久麻豆| 视频一区二区中文字幕| 国产日韩成人精品| 在线日韩一区二区| 黄色资源网久久资源365| 中文字幕一区二区三区四区不卡 | 91片在线免费观看| 青青草国产成人av片免费| 国产欧美一区二区三区在线看蜜臀 | 亚洲国产欧美一区二区三区丁香婷| 欧美电影免费观看高清完整版在 | 亚洲www啪成人一区二区麻豆| 久久久99精品久久| 91福利视频网站| 黄一区二区三区| 亚洲一区免费观看| 国产人成亚洲第一网站在线播放| 欧美系列在线观看| 国产成人午夜视频| 午夜欧美电影在线观看| 日本一区二区三区四区在线视频| 欧美日韩成人综合| 波多野结衣中文字幕一区二区三区 | 26uuu精品一区二区在线观看| 91成人在线精品| 国产麻豆视频一区二区| 亚洲国产综合人成综合网站| 国产无遮挡一区二区三区毛片日本| 欧美中文字幕一二三区视频| 国产精品亚洲第一区在线暖暖韩国| 一区二区三区波多野结衣在线观看 | 卡一卡二国产精品| 亚洲一区在线观看免费| 国产欧美一区二区精品忘忧草| 欧美日韩国产123区| va亚洲va日韩不卡在线观看| 麻豆精品国产传媒mv男同| 一区二区三区精品视频| 国产欧美日韩亚州综合| 日韩一区二区免费在线电影| 在线观看av一区| 成人动漫在线一区| 国产综合色在线视频区| 天天影视网天天综合色在线播放 | 老司机精品视频在线| 一区二区在线观看免费视频播放| 国产喷白浆一区二区三区| 欧美一区二区在线不卡| 欧美在线免费视屏| av在线不卡电影| 国产美女娇喘av呻吟久久| 免费日本视频一区| 亚洲香蕉伊在人在线观| 亚洲视频中文字幕| 亚洲国产精品ⅴa在线观看| 精品日本一线二线三线不卡| 欧美夫妻性生活| 欧美在线免费观看视频| 一本久久精品一区二区| 成人国产亚洲欧美成人综合网| 国内精品伊人久久久久影院对白| 日韩av二区在线播放| 亚洲电影一区二区| 亚洲一区二区三区不卡国产欧美| 综合网在线视频| 国产精品久久久久久久久晋中| 久久久久久久综合日本| 精品对白一区国产伦| 日韩三级视频在线观看| 91麻豆精品国产自产在线观看一区| 欧美亚洲禁片免费| 日本黄色一区二区| 色欧美片视频在线观看在线视频| 99久久婷婷国产| voyeur盗摄精品| 99精品国产热久久91蜜凸| 成人av小说网| bt7086福利一区国产| 成人小视频在线| 懂色av中文一区二区三区| 国产不卡免费视频| 国产寡妇亲子伦一区二区| 国产成人精品亚洲日本在线桃色 | 91在线观看成人| 99久久综合99久久综合网站| 91亚洲精华国产精华精华液| 91丨九色丨蝌蚪丨老版| 色婷婷av一区二区三区大白胸 | 欧美综合色免费| 欧美在线看片a免费观看| 欧美色窝79yyyycom| 欧美欧美欧美欧美| 日韩一级视频免费观看在线| 欧美成人猛片aaaaaaa| 亚洲精品在线观看网站| 久久久久久一二三区| 国产精品沙发午睡系列990531| 国产精品免费久久久久| 亚洲欧美一区二区三区极速播放| 一区二区在线电影| 亚洲高清免费一级二级三级| 日精品一区二区| 久久精品国产网站| 国产成人精品综合在线观看| av电影在线不卡| 欧美亚州韩日在线看免费版国语版| 欧美日韩小视频| 日韩久久久久久| 国产欧美日韩激情| 亚洲精品高清视频在线观看| 亚洲18女电影在线观看| 久99久精品视频免费观看| 国产高清视频一区| 色视频一区二区| 91麻豆精品国产自产在线| 久久亚洲私人国产精品va媚药| 亚洲国产精品ⅴa在线观看| 亚洲精品国产精华液| 日本不卡一区二区| 国产乱码精品一区二区三| av不卡在线观看| 欧美高清视频一二三区 | 中文幕一区二区三区久久蜜桃| 亚洲免费在线视频一区 二区| 日韩国产在线观看一区| 国产一区在线视频| 91网站在线观看视频| 91精品在线免费观看| 国产日韩欧美综合在线| 亚洲午夜免费福利视频| 久久66热偷产精品| 99国产精品久久久久久久久久| 欧美精品乱码久久久久久| 久久久九九九九| 一区二区三区四区视频精品免费 | 国产在线精品一区二区夜色| 99国产精品99久久久久久| 91精品国产一区二区三区蜜臀| 国产日韩欧美一区二区三区综合| 一区二区三区色| 精品一区二区三区av| 一本大道av一区二区在线播放| 欧美一级午夜免费电影| 中文字幕一区二区三区在线播放 | 99热99精品| 日韩美女一区二区三区四区| 亚洲色图一区二区三区| 麻豆成人在线观看| 一本久道久久综合中文字幕| 精品国精品自拍自在线| 亚洲精品国久久99热| 国产一区二区调教| 欧美日韩免费一区二区三区 | 欧美国产一区二区| 日韩高清不卡在线| 99这里都是精品| 精品国产乱码久久久久久1区2区| 一区二区视频免费在线观看| 国产自产高清不卡| 欧美伦理影视网| |精品福利一区二区三区| 久草热8精品视频在线观看| 欧美性欧美巨大黑白大战| 国产精品美女一区二区三区| 麻豆精品视频在线观看免费| 91久久香蕉国产日韩欧美9色| 久久久精品影视| 蜜芽一区二区三区| 欧洲国产伦久久久久久久| 中文一区二区在线观看|