Radar is an electronic device that detects pl...

Radar is an electronic device that detects planes， ships， coastlines， landmarks， and even storm clouds． The name radar comes from the first letters of the words radio direction and ranging． As the human eye uses light waves to see， radar "sees" with radio waves． Without radar， planes could not land safely in bad weather and ships could not move safely in thick fog．1.

In the 1800s it was discovered that radio waves could be reflected from objects． But scientists did not make great advances in radar research until the 1930s， when the world was threatened by war．2.It has been used widely in almost every conflict since then．

Echoes make it possible for radar to work． When a beam of radio waves is sent out， it strikes on an object and returns an echo． This echo is picked up by radar and recorded on a screen similar to television screen． On the screen an observer sees a flash， or a blip， that shows the direction and distance of the object．3.

Airport control towers use radar to guide planes in for safe landings． Almost all large ships depend on radar to prevent collisions with icebergs or other ships．4.Weather forecasters "see" the size， direction， and speed of storms on radar screens． Astronomers can even use radar to measure accurately the distance to the moon． Thus， the device has generated major advancements．

5.Huge radar antennas have been installed all over the United States． They guard us against possible enemy attacks． We have ballistic-missiles （战略导弹）warning systems that can alert us to attacks when missiles are more than 1，000 miles away． Other radar systems warn us against enemy aircraft and even spying space satellites．

A．Police track speeders in radar-equipped cars．

B．These measurements are now highly accurate．

C．The device can be used in a wide range of fields．

D．It is therefore especially valuable to shippers and travelers．

E．During World War II many countries used radar effectively．

F．Today radar is used by commercial airliners and weather forecasters．

G．Strengthening national defense is one of radar's most important functions．

高三英语阅读理解困难题查看答案及解析

It seems that electronic devices just keep getting smaller. Scientists in the United States have announced the creation of the first transistor with only two dimensions（二维）.

A transistor is a small electronic device that transfers or carries electronic current. Scientists hope these new 2D transistors will be used for building high-resolution（高分辨率）displays that need very little energy.

Two groups of scientists created these 2D transistors. They report that the transistors are only a few atoms thick.

Usually transistors are made with the element silicon（硅）. Computer processors, memory chips, TV screens and other electronic devices contain billions of silicon-based transistors. But these very small electrical parts have certain limitations.

Dimitris Ioannou is an electrical engineering professor at George Mason University. He says the traditional transistor has been improved as much as it can be.He adds that researchers have been looking for new materials with special features and they want transistors to be seen through and soft.

“If the layers are very thin, the transistor can become flexible, so it doesn't have to be rigid（坚硬的）, like it would be in a silicon chip. So people can think of applications like wearable electronics, television screens and other things,” said Ioannou.

These new transistors can also carry higher current. They also can move the current much faster than traditional transistors. This is important for high-definition screens.

Dimitris Ioannou says the scientific success could prove very useful in the future. "Now, how good and how useful it will be, it's still in the stage of research, but it certainly is an advance," said Ioannou.

1.Which of the following statements about the newly created transistor is TRUE?

A. They are expected to be used in high-resolution displays.

B. The transistors are made with the element silicon.

C. They are rigid, just like traditional transistors.

D. They have already been put into actual use.

2.What does the underlined sentence in Paragraph 5 mean?

A. The traditional transistors have been changed into two-dimensional ones.

B. Many of the traditional transistors have been improved over the years.

C. The traditional transistor has been developed to its fullest.

D. The traditional transistor has been developed quite well.

3.What is Dimitris Ioannou's attitude towards the creation of the new transistors?

A. Negative.　　 B. Neutral.

C. Indifferent.　　 D. Positive.

高三英语阅读理解困难题查看答案及解析

It seems that electronic devices just keep getting smaller. Scientists in the United States have announced the creation of the first transistor with only two dimensions（二维）.

A transistor is a small electronic device that transfers or carries electronic current. Scientists hope these new 2D transistors will be used for building high-resolution（高分辨率）displays that need very little energy.

Two groups of scientists created these 2D transistors. They report that the transistors are only a few atoms thick.

Usually transistors are made with the element silicon（硅）. Computer processors, memory chips, TV screens and other electronic devices contain billions of silicon-based transistors. But these very small electrical parts have certain limitations.

Dimitris Ioannou is an electrical engineering professor at George Mason University. He says the traditional transistor has been improved as much as it can be.He adds that researchers have been looking for new materials with special features and they want transistors to be seen through and soft.

“If the layers are very thin, the transistor can become flexible, so it doesn't have to be rigid（坚硬的）, like it would be in a silicon chip. So people can think of applications like wearable electronics, television screens and other things,” said Ioannou.

These new transistors can also carry higher current. They also can move the current much faster than traditional transistors. This is important for high-definition screens.

Dimitris Ioannou says the scientific success could prove very useful in the future. "Now, how good and how useful it will be, it's still in the stage of research, but it certainly is an advance," said Ioannou.

1.Which of the following statements about the newly created transistor is TRUE?

A. They are expected to be used in high-resolution displays.

B. The transistors are made with the element silicon.

C. They are rigid, just like traditional transistors.

D. They have already been put into actual use.

2.What does the underlined sentence in Paragraph 5 mean?

A. The traditional transistors have been changed into two-dimensional ones.

B. Many of the traditional transistors have been improved over the years.

C. The traditional transistor has been developed to its fullest.

D. The traditional transistor has been developed quite well.

3.What is Dimitris Ioannou's attitude towards the creation of the new transistors?

A. Negative.　　 B. Neutral.

C. Indifferent.　　 D. Positive.

高三英语阅读理解困难题查看答案及解析

For many people, being without any electronic devices (设备) creates an uneasy feeling. I recently experienced a weekend without __________. Allow me to share my ________.

Last month, my family and I drove to my aunt Nan's home. My aunt was preparing to move closer to us. The _________ of our visit was to help her pack her belongings. During the ride, my dad __________ us that Aunt Nan's style of living was _________. We wouldn't hear cell phones ring because signals for electronic devices are not _________ in the mountains. My dad also told us that Aunt Nan had a television, but it _________ few channels.My mother added that my aunt doesn't own a computer and that I would need to write my English paper on Aunt Nan's typewriter.

Once we finally _________ Aunt Nan's house, we packed household items. Very quickly, however, I realized that it was __________ to figure out what to do in my free moments. I was used to watching television or movies in my _________ time. I was becoming restless (焦虑的)．

I'm sure that adults you know _________ tell you stories about the games they played and how they had time to think quietly when they were our age.Our parents grew up in a time when electronic devices were not advanced, _________ instant communication with friends and family wasn't even possible.

Once the packing was __________， there seemed to be nothing else to do. All the quiet thinking time made me _________， so I began writing my English paper. The old typewriter was fun to use, but I had to be a lot more _________ about making typing mistakes since there was no delete key. The best part of _________ the typewriter was hearing the sound that the keys made.

I soon finished my paper. My __________ had time to hike, draw, and make unusual crafts — much like my parents did. The _________ of putting these ideas on paper made me think that our dependence on electronics has _________ our creativity. I challenge you to spend a day without _________ any electronic devices. Maybe you will discover the benefit of thinking quietly as well.

1.A.games　　　　　　 　　 B．televisions　　　　 C．electronics　 　　 D．sports

2.A.feeling　 　　　　　　 B．belongings　　　　　 C．experience　 　　　 D．devices

3.A.value　 　　　　　　　　 B．purpose　　　　　　　 C．plan　 　　　　　　　 D．result

4.A.blamed　 　　　　　　　 B．advised　　　　　　　 C．announced　 　　　　 D．informed

5.A.primitive　　 　　　　 B．modern　　　　　　　　 C．new　 　　　　　　　　 D．casual

6.A.stable 　　　　　　 B．visible　　　　　　　 C．direct　 　　　　　　 D．confusing

7.A.saved　 　　　　　　　　 B．received　　　　　　 C．accepted　 　　　　 D．refused

8.A.complained about　 B．arrived at　　　　　 C．left for 　　　　 D．cleaned up

9.A.safe　 　　　　　　　　 B．impossible　　　　　 C．difficult　 　　　　 D．easy

10.A.waiting　 　　　　 B．travelling　　　　　 C．spare 　　　　　　　 D．busy

11.A.finally　 　　　　　　 B．hardly　　　　　　　　 C．seldom　 　　　　　　 D．frequently

12.A.though　 　　　　　　 B．if　　　　　　　　　　 C．for　 　　　　　　　　 D．so

13.A.finished　 　　　　 B．included　　　　　　 C．paid　 　　　　　　　 D．opened

14.A.curious　 　　　　　　 B．uncomfortable　　　 C．angry　 　　　　　　 D．uninterested

15.A.careful 　　　　　 B．scared　　　　　　　　 C．excited 　　　　 D．crazy

16.A.holding　 　　　　　　 B．using　　　　　　　　 C．fixing　 　　　　　　 D．packing

17.A.characters　 　　　　 B．friends　　　　　　　 C．relatives　　　 　 D．classmates

18.A.process　 　　　　　　 B．story　　　　　　　　 C．idea　 　　　　　　　 D．beginning

19.A.failed　 　　　　　　 B．encouraged　　　　　 C．dulled 　　　　　 D．developed

20.A.turning down　 　　 B．turning up　　　　　 C．turning off　 　　 D．turning on

高三英语完形填空中等难度题查看答案及解析

In 1948, three American scientists invented ____ transistor, which is ____ small electronic device to control an electric current.

A．the; a            B．a; a              C．the; the           D．a; the

高三英语单项填空中等难度题查看答案及解析

The networked computer is an amazing device. It is the first media machine that serves as　 the mode of production (you can make stuff), means of distribution (you can upload stuff to the network), site of _____ (you can download stuff and interact with it), and place of praise　　　 and criticism (you can comment on the stuff you have downloaded or uploaded). _____, the computer is the 21st century’s culture machine.

But for all the reasons there are to _____ the computer, we must also act with caution.　 This is because the networked computer has started a secret war between downloading and uploading—between passive consumption and active　 _____—whose outcome will shape　　 our collective future in ways we can only begin to imagine.

All animals download, but only a few upload anything besides faces and their own bodies. Humans are _____ in their capacity to not only make tools but then turn around and use them to create superfluous( 过 剩 的 ) material goods (paintings, sculpture and architecture) and superfluous experiences (music, literature, religion and philosophy). _____, it is precisely　　 these superfluous things that define human culture and ultimately what it is to be human. Downloading and consuming culture requires great　 skills, but _____ to　 move　 beyond downloading is to rob oneself of a defining ingredient of humanity.

Despite the possibilities of our new culture　 machines, most people are　 still _____ download mode, brought about by television watching. Even after the _____ of widespread social media, a pyramid of production remains, with a small number of people uploading material, a slightly larger group commenting on or modifying that content, and a huge percentage　 remaining satisfied to just _____.

The networked computer offers the first chance in 50 years to _____ the flow caused　　 by TV viewing, to encourage thoughtful downloading and, even more importantly, meaningful uploading. The computer offers the opportunity to bring about a complete _____ from the　　 culture of television and a shift from a consumption model to a production model. This is　 a historic opportunity. Fifty years of television dominance has given birth to an unhealthy culture. The _____ is now in our collective grasp. It involves controlling our intake, or downloading, and _____ our levels of activity—uploading.

Of course people will still download. Nobody uploads more than a tiny percentage of the culture they consume. But using the networked computer as a download-only device, or even a download-mainly device, is a _____ opportunity that history affords us. Therefore, the goal must be to establish a balance between consumption and production.

1.A.celebration B.conversations C.reception D.ceremonies

2.A.Without doubt B.In return C.In particular D.By contrast

3.A.liberate B.celebrate C.concern D.reject

4.A.request B.support C.defense D.creation

5.A.unique B.familiar C.efficient D.loyal

6.A.In addition B.In fact C.For instance D.By the way

7.A.striving B.comparing C.failing D.attempting

8.A.optimistic about B.unfamiliar with C.stuck in D.ashamed of

9.A.transformation B.emergence C.encounter D.maintenance

10.A.consume B.neglect C.combine D.innovate

11.A.enhance B.quicken C.reverse D.extend

12.A.outcome B.exposure C.break D.evolution

13.A.puzzle B.cure C.regret D.favor

14.A.analyzing B.maintaining C.featuring D.increasing

15.A.wasted B.treasured C.multiplied D.revised

高三英语完形填空困难题查看答案及解析

Three days after the aircraft went missing, an international effort ________ ships and planes hasn't found any wreckage, ________ growing frustration for the families of the 239 people on board.

A. involved; causing　　　　 B. to involve; caused

C. involving; causing　　　 D. involving; having caused

高三英语单项填空中等难度题查看答案及解析

Three days after the aircraft went missing, an international effort ________ ships and planes hasn't found any wreckage, ________ growing frustration for the families of the 239 people on board.

A. involved; causing

B. to involve; caused

C. involving; causing

D. involving; having caused

高三英语单项填空中等难度题查看答案及解析

Three days after the aircraft went missing, an international effort ________ ships and planes hasn't found any wreckage, ____ growing frustration for the families of the 239 people on board.

A. involved; causing　　　 B. to involve; caused

C. involving; causing　　　 D. involving; having caused

高三英语单项填空中等难度题查看答案及解析

These days, teenagers often have their noses buried in a cellphone or other electronic devices. They are often so ______ with what’s happening on social media that they often ______ what’s going on around them.

But you ______ can’t say that about this 17-year-old. Seeing ______ the teen helped an elderly woman who was ______ at the Dollar General just restored my　 ______ in our youth!

17-year-old Senquavlous Driver joined his ______, Connie, for a trip to the Dollar General. They’d put down their shopping and were starting to pull out when Senquavious noticed a woman in her eighties struggling to get out of her ______. She succeeded but was having trouble walking. Senquavious wasted no time coming to the ______!

The teen jumped out of his aunt’s car without hesitation. He helped the elderly woman to the sidewalk and ______ with her into the store. She was there to get soda, but could hardly walk. The woman explained that she’d recently ______, hurting her back and face. So, Senquavious stayed with her the whole time, helping her get her shopping done, and then saw her back to her car.

His aunt watched on, ______ by her nephew’s compassion. She pulled out her cellphone and took some photos. “I was in ______ taking pictures because he didn’t hesitate to help her, and that made me happy,” she said.

Connie proudly ______ the photos of her nephew’s act of ______ on Facebook, saying, “I hope he continues to do great things in his life. ”

1.A.concerned B.associated C.satisfied D.pleased

2.A.remind B.review C.ignore D.notice

3.A.generally B.actually C.basically D.certainly

4.A.why B.how C.when D.if

5.A.moving B.complaining C.struggling D.driving

6.A.interest B.faith C.respect D.delight

7.A.aunt B.mother C.teacher D.grandma

8.A.car B.store C.home D.sidewalk

9.A.conclusion B.rescue C.end D.point

10.A.dealt B.stopped C.continued D.began

11.A.driven B.walked C.played D.fallen

12.A.amazed B.inspired C.attracted D.touched

13.A.sweat B.tears C.relief D.silence

14.A.chose B.remembered C.shared D.described

15.A.bravery B.kindness C.sympathy D.gratitude

高三英语完形填空中等难度题查看答案及解析