act as 臨時(shí)性充當(dāng).擔(dān)任 We went to Canada to travel and my cousin as our guide. A. played B. showed C. acted D. performed act待考短語(yǔ):act out 用手勢(shì)和語(yǔ)言表演,act on / upon 按照--行動(dòng).對(duì)--起作用 查看更多

 

題目列表(包括答案和解析)

Scientists from South Korea are trying to convert(轉(zhuǎn)化)sound waves into electricity. The research could lead to charging a cell phone from a conversation or providing energy to the nation’s electricity system generated(產(chǎn)生)by the noise during rash-hour traffic.
“Just as speakers transform electrical signals into sound, the opposite process —turning sound into a source of electrical power — is possible,” said Young Jun Park and Sang-Woo Kim, the joint authors of a new article in the journal Advanced Materials.
Harvesting energy from phone calls and passing cars is based on materials known as piezoelectrics. When bent, piezoelectric materials turn that mechanical energy into electricity. Lots of materials are piezoelectric: cane sugar, quartz (石英)and even dried bone which could create an electrical charge when stressed. For decades, scientists have pumped electricity into piezoelectric materials for use in environmental sensors, speakers and other devices.
Over the past few years, however, scientists have made dramatic advances in getting electricity out of piezoelectric devices. In an experiment, by using sound waves, which at 100 decibels(分貝)were not quite as loud as a rock concert (a normal conversation is about 60-70 decibels), the South Korean scientists produced a mild electrical current of about 50 millivolts(毫伏). The average cell phone requires a few volts to function, several times the power this technology can currently produce.
“But the real question is whether there is enough surrounding noise to act as a power source as for a cell phone,” said McAlpine, a leading scientist. A consumer probably wouldn’t want to attend a rock concert or stand next to a passing train to charge his cell phone. The South Korean scientists agree but they expect to get a higher power output as they continue their work.
【小題1】According to the two South Korean scientists, ________.

A.sound waves can travel faster than electricity
B.new materials can send cell phone signals better
C.using cell phones adds to heavy traffic in rush hour
D.electricity and sound can be transformed into each other
【小題2】We know from the passage that piezoelectric materials ________.
A.can produce electricity when stressed
B.a(chǎn)re good at changing electricity into sound
C.can reduce the noise of passing cars
D.have been widely used in phones and cars
【小題3】It can be inferred from the South Korean scientists’ experiment that ________.
A.it is hard to change sound into electricity under current conditions
B.it is impossible to make use of loud sound
C.the technology has a long way to go to have a practical use
D.the technology can power cell phones easily
【小題4】What McAlpine doubts about the technology is ________.
A.the noise pollutionB.the sound resource
C.the cost of piezoelectricsD.the safety of devices

查看答案和解析>>

假定英語(yǔ)課上老師要求同桌之間交換修改作文,請(qǐng)你修改你同桌寫(xiě)的以下作文。文中共有10出語(yǔ)言錯(cuò)誤。每句中最多有兩處,每處錯(cuò)誤僅涉及一個(gè)單詞的增加、刪除或修改。

增加:在缺詞處加一個(gè)漏字符號(hào)(),并在其下面寫(xiě)出該加的詞。

刪除:把多余的詞用斜線(\)劃掉

修改:在錯(cuò)的詞下劃一橫線,并在該詞下寫(xiě)出修改后的詞

注意:1.沒(méi)處錯(cuò)誤及其修改均限一詞;

2.只允許修改10處,多者(從第11處起)不計(jì)分。

May 10,2009                                                               Fine

Today I was having a PE lesson while I fell down and hurt my foot. I was in greatly pain at that moment,      but I tried to act as if nothing has happened until the class was over. Though I had difficulty walk back to      my classroom, I still didn’t tell anyone but even refused the offer of help of my classmates. As result, the hurt in my foot become worse. Now I know I was wrong. We can tell others our need for help and accept his help. Some day we can not help others in return. In this way, we can get along to each other happily and peacefully.

 

查看答案和解析>>

When a group of children politely stop a conversation with you, saying: “We have to go to work now,” you’re left feeling surprised and certainly uneasy. After all, this is the 1990s and the idea of children working is just unthinkable. That is, until you are told that they are all pupils of stage schools, and that the “work” they go off to is to go on the stage in a theatre.

  Stage schools often act as agencies(代理機(jī)構(gòu))to supply children for stage and television work. More worthy of the name “stage school” are those few places where children attend full time, with a training for the theatre and a general education.

  A visit to such schools will leave you in no doubt that the children enjoy themselves. After all, what lively children wouldn’t settle for spending only half the day doing ordinary school work, and acting, singing or dancing their way through the other half of the day?

 Then of course there are times for the children to make a name and make a little money in some big shows. Some stage schools give their children too much professional work at such a young age. But the law is very tight on the amount they can do. Those under 13 are limited to 40 days in the year; those over 13 to 80 days.

 The schools themselves admit that not all children will be successful in the profession for which they are being trained. So what happens to those who don’t make it? While all the leading schools say they place great importance on children getting good study results, the facts seem to suggest this is not always the case.

 People would stop feeling uneasy when realizing that the children they’re talking to________.

    A. attend a stage school      B. are going to the theatre

    C. have got some work to do     D. love singing and dancing

   In the writer’s opinion, a good stage school should ________.

    A. produce star performers

    B. help pupils improve their study skills

    C. train pupils in language and performing arts

    D. provide a general education and stage training.

 “Professional work” as used in the text means ________.

    A. ordinary school work       B. money-making performances

    C. stage training at school      D. acting, singing or dancing after class

  Which of the following best describes how the writer feels about stage schools?

    A. He thinks highly of what they have to offer.    

    B. He favours an early start in the training of performing arts.

    C. He feels uncomfortable about children putting on night shows.

    D. He doubts the standard of ordinary education they have reached.

查看答案和解析>>

It was the first snow of winter—an exciting day for every child but not for most teachers. Up until now, I had been old enough to dress myself, but today I would need some help.Miss Finlayson, my kindergarten teacher, had been through first snow days many times, but I think she must still remember this one.

I managed to get into my wool snow trousers. But I struggled on my jacket because it didn't fit well.It was a hand-me-down from my brother, and it made me wonder why I had to wear his ugly clothes. At least my hat and scarf were mine, and they were quite pretty. Finally it was time to have Miss Finlayson help me with my boots(靴子).

In her calm, motherly voice she said, "By the end of winter, you will all be able to put on your own boots.” I didn't realize at time that this was more a statement of hope than of confidence(信心).

I handed her my boots and stuck out my foot. Like most children, I expected grown-ups to do all the work. After much pushing, she managed to get the first one into place and then, with a sigh(嘆氣)worked the second one on too.

I said, "They're on the wrong feet.”

She struggled to get the boots off and went through the joyless task of putting them on again.

"They're my brother's boots, you know," I said. "I hate them".

Somehow, from long years of practice, she managed to act as though I wasn't an annoying(煩人的)little girl. She pushed and pushed, gently this time. With a greater sigh, seeing the end of her struggle with me,she asked, "Now, where are your mittens(連指手套)?’’

I looked into her eyes and said, "I didn't want to lose them, so I hid them in the toes of my boots.”

1.The little girl was more satisfied with her_.

A.trousers          B.jacket            C.boots             D.hat

2.Miss Fmlayson had difficulty with the girl's boots mainly because_.

A.the girl got them from her brother

B.the girl put something in them

C.they were on the wrong feet

D.they did not fit the girl well

3.Why does the author Miss Finlayson would remember that first snow day?

A.Because the little girl was in her brother's clothes.

B.Because it was the most exciting day of the winter.

C.Because the little girl played a trick on her.

D.Because the little girl wore a pretty scarf.

4.We can learn from the text that Miss Finlayson         

A.was losing confidence in the little girl.

B.gradually lost patience with the little girl.

C.became disappointed with the little girl.

D.was getting bored with the little girl.

 

查看答案和解析>>

One day last September, as Britney Spears was about to board a flight to Los Angeles from London, a blue bottle fell out of her purse. She quickly put it back in, but not before the camera recorded the event. Neither Spears nor her spokesman was willing to comment on the contents of the bottle, but the next morning London’s Daily Express published a page of pictures under the headline “EXCLUSIVE: POP PRINCESS SPOTTED AT AIRPORT WITH POT OF SLIMMING TABLETS.” Spears was apparently carrying Zantrex-3, one of the most popular weight-loss pills now sold in the United States. The pill, which is sold at about fifty dollars for a month’s supply, contains a huge amount of caffeine, some green tea, and three common South American herbs that also act as stimulants (興奮劑). It hit the U.S. market last March and has had a success that would be hard to overstate. Millions of bottles have been sold, and during the Christmas season it was displayed in the windows of the nation’s largest chain of vitamin shops, G.N.C. (It is so highly sought after that many of the stores keep it in locked counters.) Zantrex-3 is also sold at CVS, Rite Aid, Wal-Mart, and other chains, and over the telephone and on the Internet. If you type “Zantrex” into Google, more than a hundred thousand pieces of information about it will appear. At any moment, there are scores of people sell it on eBay.

Perhaps the most interesting thing about the success story of Zantrex-3, however, is that it is far from unique. There are hundreds of similar products on the market today, and they are bought by millions of Americans. And though Zantrex’s producer makes some exciting statements (“the most advanced weight control compound (化合物)period”), so do the people who sell Stacker 2 and Anorex along with those who sell Carb Eliminator and Fat Eliminator. Almost all of these compounds suggest that they can help people lose weight and regain lost energy, and often without diet, exercise, or any other effort.

51. Britney Spears is a / an______.

   A. dancer          B. singer           C. athlete         D. chemist

52. Which of the following is also a kind of weight-loss pill?

   A. CVS           B. Rite Aid          C. Wal-Mart       D. Anorex

53. The underlined part of the sentence in the first paragraph is most likely similar in meaning to ______.

   A. it is difficult to say how successful Zantrex-3 is

   B. you can’t overstate the success of Zantrex-3

   C. you can’t think too highly of the success of Zantrex-3

   D. Zantrex-3 is not very successful

54. From the second paragraph we know that ______ .

   A. Zantrex-3 is one of the successful weight-loss pills on the US market

   B. Zantrex-3 is the most successful weight-loss pills on the US market

C. Zantrex-3 is the only weight-loss pill on the US market

D. there are five kinds of weight-loss pills on the US market

55. The text mainly tells us ______.

   A. when Britney Spears was found taking weight-loss pills with her

   B. how Zantrex-3 became successful in the USA

   C. weight-loss pills are very popular in the USA

   D. Zantrex-3 is forbidden to be sold on the US market

查看答案和解析>>


同步練習(xí)冊(cè)答案