日日人人_亚洲美女在线视频_av手机在线播放_国产大片aaa_欧美中文日韩_午夜理伦三级

精英家教網 > 高中英語 > 題目詳情

A black hole is a place in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Because no light can get out, people can’t see black holes. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently from other ones.
Black holes can be big or small. Scientists think the smallest black holes are as small as just one atom. These black holes are very tiny but have the mass of a large mountain. Mass is the amount of matter, or “staff”, in an object.
Another kind of black hole is called “stellar”(星球黑洞). Its mass can be up to 20 times more than the mass of the sun. There may be many stellar mass black holes in Earth’s galaxy. Earth’s galaxy is called the Milky Way.
The largest black holes are called “supermassive”(超大質量黑洞). These black holes have masses that are more than one million suns together. Scientists have found proof that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy has a mass equal to about four million suns and would fit inside a very large ball that could hold a few million Earths.
Scientists think the smallest black holes formed when the universe began. Stellar black holes are made when the center of a very big star falls in upon itself, or falls apart. When this happens, it exploded part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in.
A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. But scientists can see how the strong gravity affects the stars and gas around the black hole. Scientists can study stars to find out if they are flying around, or orbiting a black hole.
When a black hole and a star are close together, high-energy light is made. This kind of light cannot be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light.
【小題1】The gravity of a black hole may become so strong that light cannot get out when ____________.

A.the star is going to die
B.special tools are used on it
C.other stars come close to it
D.it is seen from the space telescopes
【小題2】According to the passage, which of the following is NOT true?
A.A black hole can be very tiny but extremely heavy.
B.The gravity of a black hole holds all light in its center.
C.Scientists observe high-energy light through their own eyes.
D.Some small black holes came into being as early as the universe.
【小題3】The underlined word “galaxy” in Paragraph 5 means __________.
A.a black holeB.the Milky Way
C.a series of starsD.a planet near the earth
【小題4】What does the last sentence in Paragraph 5 suggest?
A.Neither the sun nor the earth is as heavy as a black hole.
B.There is a supermassive black hole at the center of the Milky Way.
C.The supermassive black hole had existed before the Milky Way was formed.
D.There is a reason why the large black holes are called “supermassive”.
【小題5】The last two paragraph mainly focus on the question of _________.
A.what a black hole is
B.how black holes form
C.how big black holes are
D.how scientists know about black holes


【小題1】A
【小題2】C
【小題3】C
【小題4】D
【小題5】D

解析試題分析:文章介紹黑洞的形成,它的特點以及科學家探索研究黑洞的方法。
【小題1】細節題:根據文章第一段中“This can happen when a star is dying.”可知恒星的死亡可能會形成黑洞。故選A。
【小題2】細節題:根據第三段中“These black holes are very tiny but have the mass of a large mountain”這些黑洞可能會非常小,但是有一座山一樣的質量,可知A正確;根據倒數第二段中“A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole.”黑洞不可見是因為強大的引力將所有的光線吸進黑洞的中間,可知B項正確;根據最后一句“Scientists use satellites and telescopes in space to see the high-energy light.”科學家們使用衛星和太空望遠鏡查看高能光,可知科學家不是用自己的眼睛,因此C錯誤;根據第六段中“Scientists think the smallest black holes formed when the universe began.”科學家認為最小的黑洞在宇宙開始時形成,可知D項正確。故選C。
【小題3】推理題:根據第四段中“Earth’s galaxy is called the Milky Way”地球所在的星系叫銀河系,常理可知星系是有很多星星組成的。故選C。
【小題4】推理題:根據第五段最后一句“The supermassive black hole at the center of the Milky Way galaxy has a mass equal to about four million suns and would fit inside a very large ball that could hold a few million Earths.”在銀河系中心的超大質量黑洞的質量相當于四百萬個太陽,是一個可以容納幾百萬地球在內的巨大的球,由此可知這是在解釋什么叫做“超大質量黑洞”。故選D。
【小題5】推理題:閱讀最后兩段內容可知是在介紹科學家是如何找到黑洞的。故選D。
考點:考查科普教育類閱讀

練習冊系列答案
相關習題

科目:高中英語 來源: 題型:閱讀理解

October 15th is the Global Handwashing Day. Activities are planned in more than 20 countries to get millions of people in the developing world to wash their hands with soap. For example, donors(捐贈者) will give 150,000 bars of soap to schools in Ethiopia.
Experts say people around the world wash their hands every day, but very few use soap at so-called important moments. These include after using the toilet, after cleaning a baby and before touching food.
Global Handwashing Day is the idea of the Public-Private Partnership for Handwashing with Soap. Partners include the United Nations Children’s Fund, American government agencies, the World Bank and soap makers Unlever and Procter and Gamble. The organizers say all soaps are equally effective at removing disease-causing germ(細菌). They say the correct way to wash is to wet your hands with a small amount of water and cover them with soap. Rub(揉搓) it into all areas, including under the fingernails(指甲). Rub for at least twenty seconds. Then rinse well under running water. Finally, dry your hands with a clean cloth or wave them in the air.
The Partnership for Handwashing says soap is important because it increases the time that people spend in washing hands. Soap also helps to break up the dirt that holds most of the germs. And it usually leaves a pleasant smell. The Partnership for Handwashing also says washing with soap before eating or after using the toilet could save more lives than any vaccine(疫苗)or medicine. Hand washing could also prevent the spread of other diseases. When people get germs on their hands, they can infect(感染)themselves by touching their eyes, noses or mouths. Then they can infect others.
【小題1】What’s the best title for this passage?

A.Say no to washing hands in the wrong way.
B.Find out why washing hands carefully is so important.
C.Hand washing: so important----it gets a day of its own.
D.Want to live a longer life?-wash your hands.
【小題2】The word “rinse” in Paragraph 3 probably means ______.
A.to dry your hands B.to wash away the soap
C.to rub your hands carefully D.to clean your fingers
【小題3】The last paragraph mainly tells us ______.
A.how to wash your hands correctly
B.why washing hand with soap is so important
C.the dangers of washing hands without soap
D.when we should especially wash our hands with soap
【小題4】In which part of newspaper would you most probably read this passage?
A.Medical care B.Public service C.Health report D.Advertisement

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

Mulch is a protective cover of material that is spread on top of soil.It is usually made out of organic material, like crop waste.Farmers may keep the remains of maize or other crops on top of the soil.This creates mulch on the soil surface.The plant remains help protect the soil against wind and water damage.Mulching is one of the best things people can do for their plants.It also helps keep the soil from getting dry, and reduces the need for watering plants.It also limits temperature changes in the soil.And it stops unwanted plants, or weeds,from growing.
Organic mulch improves the condition of soil.As the mulch breaks down, it provides material which keeps the soil from getting hard.This improves the growth of roots and increases the movement of water through the soil.It also improves the ability of the soil to hold water. Organic mulch contains nutrients for plants.It also provides a good environment for earthworms and other helpful organisms in the soil.
It is easy to find organic mulch materials.Cut­up leaves and small pieces of tree bark can be used.Grass cuttings are also a good mulch for plants. Mulch from newspapers works well in controlling weeds.
The best time to add mulch depends on your goal.Mulch provides a thick barrier between the soil and the air.This helps to reduce temperature changes in the soil. As a result,mulched soil will be cooler than other soil in the summer.In winter, the mulched soil may not freeze as deeply as other soil.The best time is after the ground has frozen, but before the coldest weather arrives.Spreading mulch before the ground has frozen may attract small animals searching for a warm place to spend the winter.Delaying the spreading should prevent this problem.The animals will probably find another place to live.
【小題1】The author tells us the following EXCEPT________.

A.what mulch is and its benefits
B.the best time to add mulch
C.what can be mulched on the soil surface
D.the bad effects of mulch
【小題2】The following can be used as organic materials to make mulch EXCEPT________.
A.tree barks B.cut­up leaves
C.grass cuttings D.plastic
【小題3】Which of the following is the benefit of mulch?
A.Protecting the soil against wind and water damage.
B.Keeping the soil wet and reducing the need for watering plants.
C.Reducing temperature changes in the soil and stopping unwanted weeds
growing.
D.All of the above.
【小題4】The main idea of Paragraph 2 is that organic mulch can________.
A.improve the condition of soil
B.improve the ability of the soil to hold water
C.provide a good environment for earthworms
D.improve the growth of roots and increase the movement of water through the
soil
【小題5】From the last paragraph, we know ________.
A.the best time to add mulch is in spring and summer
B.the best time to add mulch is after the coldest weather arrives
C.the best time to add mulch depends on weather
D.choosing the best time to add mulch can avoid attracting small animals

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

BEIJING - By the end of 2011 China-made supercomputers will say goodbye to foreign microchips(微芯片) and start using their own "Chinese core(核心)", according to one of the country's leading scientists, Hu Weiwu.
Hu told reporters on Saturday that the "Dawning 6000" supercomputer, developed by the Institute of Computing Technology of CAS and the Dawning Information Industry Company (DIIC), will adopt Loongson microchips for the first time as its core parts. It will have a computing speed of more than 1,000 trillion operations a second.
Making supercomputers with Chinese microchips is one of the nation's major science and technology projects. Three organizations - the Institute of Computing Technology of CAS, Jiangnan Institute of Computing Technology and the National University of Defense Technology (NUDT) - have their own supercomputer projects.
According to their schedules, all three institutions will need to meet the target of using domestically(國內的) developed microchips by the end of this year. Hu said the new supercomputer will use fewer than 10,000 Loongson microchips, and will also be more energy-efficient.
Tianhe-1A, developed by NUDT in Hunan's provincial capital Changsha, is the fastest supercomputer in the world. However, Tianhe-1A largely runs on 14,336 CPUs made by Intel, and 7,186 GPUs (processing units) from Nvidia, two US chip-makers.
Hu said there will be difficulties ahead as there is little affiliated equipment specially developed for these supercomputers. "We have enough supercomputers in China but still can't make full use of them," He said.
Hu added that although the China-made CPUs have improved since they were first produced in 2002, they have a long way to go to compete with US chip-makers such as Intel.
【小題1】What’s the best title for this passage?

A.The Arrival of Chinese Supercomputers
B.Homemade CPUs with a Long Way to Go
C.The Supercomputers of Three Organizations in China
D.Homemade CPUs on the Way for Local Supercomputers
【小題2】What will raise the speed to more than 1,000 trillion operations a second.?
A.Dawning 6000B.Loongson microchips
C.DIICD.Tianhe-1A
【小題3】What do we know about Tianhe-1A?
A. Not all the parts of Tianhe-1A are made by China.
B. Tianhe-1A is developed by CAS and DIIC.
C. Tianhe-1A will use fewer than 10,000 Loongson microchips.
D. NUDT has produced a most powerful supercomputer in China.
【小題4】The underlined word “affiliated” can be replaced by_______.
A.cheapB.suitableC.expensiveD.modern

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

In the second half of each year, many powerful storms are born in the tropical Atlantic and Caribbean seas. Of these, only about a half a dozen generate the strong, circling winds of 75 miles per hour or more that give them hurricane status, and several usually make their way to the coast. There they cause millions of dollars of damage, and bring death to large numbers of people.
The great storms that hit the coast start as innocent circling disturbances (氣旋) hundreds — even thousands — of miles out to sea. As they travel aimlessly over water warmed by the summer sun, they are carried westward by the trade winds. When conditions are just right, warm, moist (潮濕的) air flows in at the bottom of such a disturbance, moves upward through it and comes out at the top. In the process, the moisture in this warm air produces rain, and with it the heat that is switched to energy in the form of strong winds. As the heat increases, the young hurricane begins to turn around in a counter-clockwise motion (反時針方向).
The average life of a hurricane is only about nine days, but it contains almost more power than we can imagine. The energy in the heat released (釋放) by a hurricane’s rainfall in a single day would satisfy the entire electrical needs of the United States for more than six months.
Water, rather than wind, is the main source of death and destroying in a hurricane. A typical hurricane brings 6-to-12-inch downpours resulting in sudden floods. Worst of all is the powerful movement of the sea — the mountains of water moving toward the low-pressure hurricane center. The water level rises as much as 15 feet above normal as it moves toward shore.
【小題1】An ordinary tropical storm is called a hurricane when ______.

A.it occurs in the Caribbean seas
B.its winds reach 75 miles per hour
C.it makes its way to the coastline
D.its winds begin to circle on the sea
【小題2】What is the worst thing about hurricane?
A.The rough water. B.The violent winds.
C.The heat it gives out. D.The length of its life.
【小題3】What does the third paragraph mainly talk about?
A.The hurricane is extraordinarily powerful.
B.The hurricane is used to generate electricity.
C.The hurricane can otherwise offer an unusual sight.
D.The hurricane can give people an unforgettable experience.
【小題4】The counter-clockwise movement of the hurricane is caused by ______.
A.the low-pressure area in the center of the storm
B.the force of waves of water
C.the increasing heat
D.the trade winds

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

You don't need to get in a time-traveling machine to see how technology will reshape our lives, such as the way we shop.Several new technologies that are to change your buying habits already exist.Let's see what's in store for your future shopping.
Try it on, virtually (虛擬的).Want to shop online for a new pair of eyeglasses? You don't need to guess which pair looks best on you. Go and see the eBay Fashion iPhone app to try a pair of eyewear you're checking out on a picture of your face.But what if you want to buy something bigger? Thanks to Microsoft Kinect's motion tracking camera, you can cover clothes on your screen body.You can even choose the background of your virtual fitting room to enrich your shopping experience.
Get a perfect, custom fit.Everyone's body is shaped differently.To get a perfect fit, you sometimes have to get your clothes changed.But by using 3D scanning technology, all the clothes you buy will fit your body perfectly.Some companies scan your body using High-tech to get the most accurate measurements, so they can make special clothes just for you.
High-tech shopping carts and checkout counters.High-tech shopping carts could, in time, be a common sight in malls and supermarkets.Microsoft Kinect-enabled carts are currently under test.The cart can follow you along the aisles (通道), controlled merely by your movement and your voice.In China, a supermarket chain introduced tablet-equipped carts that guide shoppers around the stores' aisles.
In the United States, several supermarkets use a device called Scan It that gives buyers the freedom to scan purchases on their own while they shop.While it's great not having to line up at a checkout counter, we wouldn't mind it if the store used Toshiba's new Object Recognition Scanner.The machine identifies a product as soon as it's placed in front of a camera just by its shape and color, even if it has no bar code.
【小題1】What's the best title for this text?

A.Ways for future shopping
B.Influence of new technology
C.Inventions to change habits
D.A new time-traveling machine
【小題2】According to Paragraph 2, The eBay Fashion iPhone app can _____.
A.make vivid pictures of our face
B.help us sell more clothes online
C.create us a virtual dressing room
D.choose suitable eyeglasses for us
【小題3】Which of the following can get the most accurate shape of our body?
A.Object Recognition Scanner.
B.The eBay Fashion iPhone app.
C.3D scanning technology.
D.Microsoft Kinect-enabled carts.
【小題4】The Object Recognition Scanner can identify a product more quickly by____.
A.the customer's voice
B.its shape and color
C.the customer's movement
D.the bar code on it
【小題5】What can we infer from this text?
A.Checkout counters will disappear from supermarkets in future.
B.Buyers can use Scan It to go around the supermarket by themselves.
C.High-tech shopping carts will be widely used in malls and supermarkets.
D.The new technologies are only dreams that are impossible to come true.

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

Bottled water has become the choice for people who are healthy and thirsty. Bottled water is all over the world. But some say the planet’s health, and people’s health may be suffering from it.
The idea that bottled water is safer for humans may not be true. The Natural Resources Defense Council of America said, “There is no promise that because water comes out of a bottle, it is cleaner or safer than water from the tap.” Another New York City-based action group added that some bottled water is “really just tap water in a bottle—sometimes more clean, sometimes not.”

It is not proven that bottled water is better than tap water. Nick Reeves from the Chartered Institution of Water and Environmental Management said, “The high mineral content (含量) of some bottled water makes them not good for feeding babies and young children.” Also, most bottled water doesn’t have fluoride (氟化物), which can make teeth stronger. Kids are drinking more bottled water and less fluoridated tap water, and some say that’s behind the recent rise in bad teeth.
Storing is another problem. Placed near heat, the plastic bottles can produce bad chemicals (化學物質) into the water.
According to the Environmental Protection Agency, some 2.7 million tons of plastic are used worldwide to bottle water each year. The plastic can take between 400 and 1,000 years to break down.
In terms of energy use, plastic bottles are also not cheap. One report said that if water and soft drink bottlers had used 10 percent recycled materials in their plastic bottles, they would have saved about 72 million gallons of gas.
So, if you are worried about the effect of bottled water on the Earth, you can take the following steps.
● Drink from your tap. Unless your government warns against this, it should be fine.
● Get a container (容器). Carry your tap water in a steel or a lined drinking container, and clean it between uses.
● Keep it cool. Don’t drink from a bottle that has been sitting in the sun, don’t store it near chemicals, and don’t reuse plastic bottles.
● Choose glass containers over plastic if possible. When finished, recycle!
【小題1】What is the main idea of the article?

A.Drinking tap water is the only choice for people.
B.Glass containers are better than plastic bottles.
C.Plastic bottles are harmful to the environment.
D.Bottled water may not be as good as we think.
【小題2】What can we learn about plastic bottles from the article?
A.They break down in less than 300 years.B.They can be used for many other things.
C.They are a risk to the environment.D.They are cheap to make.
【小題3】According to the article, we can know that bottled water is __________.
A.no problem for the environmentB.more expensive than tap water
C.always safer than tap waterD.better for babies
【小題4】Which of the following about tap water is NOT mentioned in the article?
A.There are a lot of problems storing tap water.
B.Bottled water can be just tap water in a bottle.
C.It may be better for your teeth.
D.It may contain fluoride.

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

What if I took that big jump on my bike?What’s the worst thing that could happen if I go out at midnight?Should try smoking?The teen years can play out like a choose-your-own-adventure novel.
Teenagers must act on an endless parade of choices.Some choices.including smoking.Come with serious consequences.As a result, adolescents often find themselves trapped between their impulsive tendencies(-Just try it!)and their newfound ability to make well-informed and logical choices(-Wait, maybe that’s not such a good idea!).
So what makes the teenager’s brain so complex? What drives adolescents-more than any other age group-to sometimes make rash or questionable decisions?
If you have ever thought that the choices teenagers make are all about exploring and pushing limits, you are on to something. Experts Experts believe that this tendency marks a necessary period in teen development.The process helps prepare teenagers to confront the world on their own. It is something all humans have evolved to experience-yes, teens everywhere go through this exploratory period.Nor is it unique to people:Even laboratory mice experience a similar stage during their development.
For example,laboratory experiments show that young mice stay close by their mothers for safety. As mice grow.their behavior does too.“When they reach puberty,they’re like,‘I’m gonna start checking out how this environment looks without my mom,…explains Beatriz Luna,of the University of Pittsburgh.
As a developmental cognitive neuroscientist,Luna studies those changes that occur in the brain as children develop into adults.She and other researchers are showing how the teen experience can lead to powerful advantages later in life.Take mice again:Young mice that explore most tend to live longest——that is,unless a cat eats them,Luna adds.
【小題1】What is the best title for the text?

A.Teenagers make endless choices
B.The teenage brain drives them to be different
C.How the teenage brain develops
D.Researches about the teenagers
【小題2】What does the underlined sentence in paragraph 4 mean?
A.It means “you are wrong”.
B.It means“you lose your way”.
C.It means“you get the point”.
D.It means“you are off the point”.
【小題3】According to the text,the teenager who explores most wiIl
A.make no mistakes in his life.
B.have advantages over others.
C.loSe his confidence even his life.
D.experience no failure and live Iongest.
【小題4】What does the writer want to tell us by taking mice for example?
A.young mice try to look for safety.
B.Young mice like to stay with their mothers.
C.Mice also experience a period to explore the world.
D.Mice experience different stages.
【小題5】What may the text discuss in the next part?
A.How call a teenager make right choices
B.Why the parents shouldn’t allow teenagers to smoke
C.What has been discovered in the lab experiment.
D.What really goes on in the teenage brain.

查看答案和解析>>

科目:高中英語 來源: 題型:閱讀理解

Surfing the Internet for fun will make you a better employee,according to an Australian study.
The University of Melbourne study shows that people who use the Internet for their own reasons at work are about 9 percent more productive than those who do not. Study author brent Coker said“Surfing the Internet at times helps increase an employee’s attention.”
“People need to relax for a bit to get back their attention,”Coker said on the university’s website.”Having a short break, such as a quick surfing of the Internet, helps the mind to rest itself,leading to a higher total Internet attention for a day’s work, and as a result, increase productivity(生產效率),”he said.
   According to the study of 300 workers ,70 percent of people who use the Internet at work surf the Internet for their own reasons during office hours. Among the most popular surfing activities are searching for information about products, reading online news, playing online games and watching videos.”Firms spend a lot of money on software to block their employees from watching video, using social networking sites or shopping online, ”said Coker.”that’s not always a good idea.”
However, Coker said the study looked at people who surfed the Internet in moderation(),or were on the Internet for lee than 20 percent of their total time in the office.”Those who spend too much time surfing the Internet will have a lower productivity than those without,”he said.
【小題1】What does the University of Melbourne study mainly show?

A.People who surf the Internet are good employees.
B.Not everyone surfs the Internet for fun during office hours.
C.Surfing the Internet for fun during office hours increase productivity.
D.The Internet is becoming more and more important in people’s life.
【小題2】According to paragraph 3,Brent Coker would most probably agree that ________.
A.the longer a person’s mind rests the better attention he will have.
B.surfing the Internet is the best way to increase productivity.
C.workers should have a long break during office hours
D.workers should let their minds rest now and then.
【小題3】Which of the following is not mentioned in the passage as one of the most popular surfing activities?
A.Watching videos.B.reading online news.
C.Reading online novels.D.Playing online games.
【小題4】The underlined word “block” in paragraph 4 means “_______”.
A.preventB.cycleC.burstD.breathe
【小題5】What can we infer from the last paragraph?
A.Spending too much time surfing the Internet reduces productivity.
B.Those who never surf the Internet have the lowest productivity.
C.Most people don’t surf the internet in modernation during office hours.
D.People should spend as little time as possible surfing the Internet.

查看答案和解析>>

同步練習冊答案
主站蜘蛛池模板: 欧美久久精品 | 五月在线视频 | 亚洲一区二区免费视频 | 另类ts人妖一区二区三区 | 午夜视频在线 | 欧美激情久久久 | 欧美一级特黄aaaaaa | 日本精品视频在线 | 国产亚洲一区二区三区 | 日本少妇高潮达到高潮 | 亚洲国产精品av | 性欧美精品 | 欧美日韩在线一区二区 | 色婷婷国产 | 日韩综合在线观看 | 97av在线| 黄色一级网站 | 久久精品导航 | 久久久三级 | 日本在线天堂 | 久久久久久黄色 | 国产精品爽爽爽 | 精品国产福利 | av色在线| 999久久久精品 | 亚洲欧美日韩另类 | 欧美www| 少妇一级淫片免费看 | 中文日韩在线 | 免费国产黄色 | 91看片在线| 欧美性影院| 久久精品视频网站 | 婷婷在线播放 | 日本www视频 | 国产深夜福利 | www.夜夜骑| 欧美激情专区 | 亚洲高清免费视频 | 日本视频一区二区三区 | 日韩一区二区在线视频 |