Messages ______ be changed from sound into el...

Messages ______ be changed from sound into electricity before they ______ be sent by radio.

A. must; will   B. have to; can      C. can; must    D. need; may

高三英语单项填空困难题查看答案及解析

Scientists from South Korea are trying to convert（转化）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（产生）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（分贝）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.

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

2.We know from the passage that piezoelectric materials ________.

A．can produce electricity when stressed

B．are good at changing electricity into sound

C．can reduce the noise of passing cars

D．have been widely used in phones and cars

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

4.What McAlpine doubts about the technology is ________.

A．the noise pollution                      B．the sound resource

C．the cost of piezoelectrics                 D．the safety of devices

高三英语阅读理解困难题查看答案及解析

Chefs typically toss（抛）the frying food into the air from deep, rounded pans or woks before catching it again. Launching rice and its fixings allows a chef to cook it over really hot flames without burning. At times, temperatures in a pan can reach 1,200。 Celsius. 1.

Scientists found that the chefs relied on a specific pattern of motion. And they repeated those motions about three times a second. 2. At the same time the wok was rocked to and fro. The chefs used the edge of the stovetop as a fulcrum（支点）on which to balance as they rocked it.

Cooks use similarly complex patterns of movement to cook up other foods. 3.

Scientists used a computer to simulate（模仿）the tracks of rice that would occur in a wok moved in various ways. Along the way, the scientists hit on some key coo king tips. The wok moved in various ways. Along the way, the scientists hit on some key cooking tips. The rocking and sliding motions shouldn’t be done at the same time. 4. Also, the wok’s movements should repeat rapidly. Moving the wok even faster could launch the rice higher. That might allow cooking at higher temperatures and perhaps a quicker meal.

5. Chefs at Chinese restaurants can struggle with shoulder pain, studies have shown. Rapidly shaking their heavy woks could be part of the problem. One solution might be a stir-frying robot. It could be built based on their new found results to take the weight off chefs’ shoulders.

A.But faster shaking may be hard on a cook.

B.To make fried rice like a professional, use science.

C.If they are, the rice won’t mix well and could burn.

D.Each repetition included sliding a wok back and forth.

E.Cooking is hard work that needs patience and perseverance.

F.The high temperature helps create the tastiest stir-fried food.

G.They will turn the pan quickly, for instance, to get smooth, flat egg cakes.

高三英语七选五中等难度题查看答案及解析

How words came into being is unknown.All we assume is that some early men invented cortain sounds,in one way or another,to express thoughts and feelings,actions and things,so that they could talk with each other.Later they agreed upon certain signs,called letters,which could be put together to show those sounds,and which could be written down.Those sounds,whether spoken or written in letters,are called words.

The power of words,then,lies in their associations-the things they bring up to our minds.Words become filled with meaning for us by experience;and the longer we live,the more certain words bring back to us the happy and sad events of our past;and the more we read and learn,the more the number of words that mean something to us increases.

Great writers are those who not only have great thoughts but also express these thoughts in words which have powerful effects on our minds and feelings.This clever use of words is what we call literary style.Above all,the real poet is a master of words.He can express his meaning in words which sing like music,and which by their position and association can move men to tears.We should therefore learn to choose our words carefully and use then correctly,or they will make our speech silly and common.

1.We learn from the text that language might have begun with(    )

A．expressions    B．actions    C．signs    D．sounds

2.What is mainly discussed in Faragraph 2?

A．The ……of new words      B．The importance of old words

C．The relation of human experience with words

D．The gradual change and development of words

3.In the last paragraph,what does the anthor suggest that we should do?

A．Use words skilfully    B．Make musical speeches

C．Learn poems by heart   D．Associate with listeners

高三英语阅读理解中等难度题查看答案及解析

E

How words came into being is unknown.All we assume is that some early men invented cortain sounds,in one way or another,to express thoughts and feelings,actions and things,so that they could talk with each other.Later they agreed upon certain signs,called letters,which could be put together to show those sounds,and which could be written down.Those sounds,whether spoken or written in letters,are called words.

The power of words,then,lies in their associations-the things they bring up to our minds.Words become filled with meaning for us by experience;and the longer we live,the more certain words bring back to us the happy and sad events of our past;and the more we read and learn,the more the number of words that mean something to us increases.

Great writers are those who not only have great thoughts but also express these thoughts in words which have powerful effects on our minds and feelings.This clever use of words is what we call literary style.Above all,the real poet is a master of words.He can express his meaning in words which sing like music,and which by their position and association can move men to tears.We should therefore learn to choose our words carefully and use then correctly,or they will make our speech silly and common.

58.We learn from the text that language might have begun with(    )

A．expressions    B．actions    C．signs    D．sounds

59.What is mainly discussed in Faragraph 2?

A．The ……of new words      B．The importance of old words

C．The relation of human experience with words

D．The gradual change and development of words

60.In the last paragraph,what does the anthor suggest that we should do?

A．Use words skilfully    B．Make musical speeches

C．Learn poems by heart   D．Associate with listeners

高三英语阅读理解简单题查看答案及解析

It will be some years before some foreign doctors change the impression they have _____Chinese medicine, _____, in their opinion, is nothing but raw herbs and not effective at all in treating diseases.

高三英语单项填空中等难度题查看答案及解析

Inside a library in a seaside town is a room changed into a cafe. There might be a homeless man _______ coffee for a sad mother, an elderly woman _______ a young man advice and strangers sharing stories. This community open space _______ to solve the central problems that commonly lead to homelessness: _______ and a lack of purpose.

It’s the _______ of Maff Potts. While working with charities for the homeless, he felt _______ because they weren’t reducing homelessness. All the shelters only helped people once they’d already lost everything, _______ trying to solve the problems that led to their homelessness in the first place. A main _______, he discovered, is that many people who ended up at the shelters were alone. Their relationships had broken down, they didn’t have a(n) _______ system, or they had no one to show them __________.

Potts understands how altruism (利他主义) can help. Over the years during his work on homelessness, when he met people in their __________ moments, Potts began asking them to do him a favour. One man __________ he’d been a painter, so Potts started __________ how the reception area could use redecorating and asked the man for his __________.The man ended up offering to __________ it himself. The task gave him a __________, a reason to keep living.

“The thing that led to a lasting transformation was when they __________ somebody else,” Potts said. “That was __________ time.”

So Potts started thinking there must be a way to __________ the lives of people who are __________ not by making them feel like they’re always receiving help, but by giving them a space to help others — and in the end, help themselves.

1.A.drinking B.making C.growing D.hiding

2.A.saving B.paying C.awarding D.offering

3.A.seeks B.deserves C.happens D.pretends

4.A.Sickness B.Tiredness C.Loneliness D.Weakness

5.A.idea B.excuse C.hobby D.feeling

6.A.shocked B.interested C.disappointed D.frightened

7.A.regardless of B.instead of C.as for D.along with

8.A.mistake B.result C.technique D.cause

9.A.support B.power C.health D.alarm

10.A.freedom B.wisdom C.kindness D.patience

11.A.latest B.funniest C.fittest D.darkest

12.A.preferred B.mentioned C.recommended D.demanded

13.A.insisting on B.hearing of C.depending on D.talking about

14.A.advice B.duty C.research D.attention

15.A.repair B.repaint C.reinvent D.replace

16.A.break B.lesson C.purpose D.promise

17.A.challenged B.invited C.helped D.recognised

18.A.familiar B.strange C.terrible D.magic

19.A.copy B.improve C.reflect D.record

20.A.struggling B.changing C.relaxing D.escaping

高三英语完形填空困难题查看答案及解析

Bringing tech into the bedroom can be more harmful than helpful. Glancing at your phone before hitting the bed may be distracting and, more important, the blue light its screen emits is known to make falling asleep more difficult. But that’s not true for all gadgets. These smart-home devices want to invade your bedroom with the aim of improving your sleep.

1.All the following gadgets help you with sleep with body contact EXCEPT ________.

A.Muse Headband B.Here One Smart Earbuds

C.Apple Iphone D.S+sleep Monitor

2.What is NOT true about blue light?

A.Frequent use of cell phones leads to much emission of blue light.

B.It makes it harder for your body to produce an essential chemical.

C.The Night Shift feature can probably reduce the emission of blue light.

D.Blue light reminds you to get to bed and regulates your sleep.

3.What’s the best title for the passage?

A.Sleep, something well deserved

B.Sleep, your name is gadget

C.Sleep, a mission made impossible

D.Sleep, highly dependent on tech

高三英语阅读理解中等难度题查看答案及解析

Think carefully before you answer questions online. You may be ______ into giving away very important personal information.

A. caught B. addicted

C. seized D. trapped

高三英语单项填空中等难度题查看答案及解析

As is expected, it will be not long before our domestically built aircraft Carriers _____ into operation.

A.will be put B.are put

C.will have been put D.have been put

高三英语单项填空中等难度题查看答案及解析