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”(超大质量黑洞). 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.
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
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.
3. Which can be inferred from the passage?
A. Every galaxy must have a black hole.
B. A galaxy is the center of the universe.
C. A galaxy consists of a large group of stars and planets.
D. Earth’s galaxy is called the Milky Way.
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 only one 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”.
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
中考解读考点精练系列答案
各地期末复习特训卷系列答案
小博士期末闯关100分系列答案科目：高中英语 来源：2015届江苏江阴祝塘中学五校联考高二下期中考试英语卷（解析版） 题型：阅读理解
How do you design a pay plan that motivates people to do their best work? A new study by three Harvard researchers suggests a novel answer: Shortly after you hire new workers, give them a raise.
"Previous research has shown that paying people more than they expect may elicit reciprocity(相互作用) in the form of greater productivity," notes Deepak Malhotra, a Harvard business-administration professor who worked on the study. What he and his colleagues found, however, was that the connection between more pay and extra effort depends on presenting the increase "as a gift—that is, as something you've chosen to do purely as a nice gesture, with no strings attached."
Malhotra and his team studied 267 people hired by oDesk, a global online network of freelancers, to do a one-time data-entry project for four hours. All of the new hires were people in developing countries, for whom hourly wages of $3 and $4 were higher than what they had been making in previous jobs.
The researchers split the group up into three equal parts. One group was told they would earn $3 an hour. A second group was initially hired at $3 an hour but, before they started working, they got a surprise: The budget for the project had expanded unexpectedly, they were told, and they would now be paid $4 an hour. The third group was offered $4 an hour from the start and given no increase.
Even though the second and third groups were eventually paid the same amount, the second group worked harder and produced more—about 20% more—than either of the other two. People in the second group also showed the most stamina, maintaining their focus all the way through the assigned task and performing especially well toward the end of the four hours. Interestingly, the more experienced employees in the high-performing group were the most productive of all, apparently because their previous work experience led them to appreciate the rarity of an unexpected raise.
Contrary to conventional wisdom, Malhotra points out that higher pay, in and of itself, didn't promote productivity: People who made $4 an hour from the beginning worked no harder than those who were hired at $3 and were then paid $3.
To get the most impact from their pay plans, he adds, companies might consider not only what to pay new hires, but when to pay it.
"The key thing is how you present [the reason for an increase]," he says. Doling out extra money could promote productivity most "if you make it clear that the pay raise is something you're choosing to do just because you can. Our theory is that people will reciprocate. If you do something nice, they'll do something nice back."
1.What does the underlined word “stamina” most probably mean?
A. The quality of being intelligent or clever.
B. The quality of doing something difficult or dangerous.
C. The physical or mental energy needed to do a tiring activity for a long time.
D. A particular method of doing an activity, usually involving practical skills.
2.Why did the second group produce more than the other two groups?
A. Because they thought they were better paid than the other groups.
B. Because they were experienced employees from developing countries.
C. Because an unexpected raise reminded them of their previous work.
D. Because they felt they were nicely treated and tried best to repay it.
3.What can we infer from this passage?
A. No pains, no gains.
B. It matters not what we give but how.
C. Honesty is the best policy.
D. Actions speak louder than words.
查看答案和解析>>
科目：高中英语 来源：2015届广东省高二下期末英语试卷（解析版） 题型：阅读理解
Millions of Americans return from long-distance trips by air, but their luggage doesn’t always come home with them. Airline identification tags（标签） can come loose, and the bags go who-knows-where. And passengers leave all kinds of things on planes.
The airlines collect the items and, for 90 days, attempt to find their owners. They don’t keep them, since they’re not in the warehouse business. And by law, they cannot sell the bags, because the airlines might be tempted to deliberately misplace luggage.
So once insurance companies have paid for lost bags and their contents, and they no longer belong to passengers, a unique store in the little town of Scottsboro, Alabama, buys them. The “Unclaimed Baggage Center,” is so popular that the building, which is set up like a department store, is the number-one tourist attraction in all of Alabama. More than one million visitors stop in each year and take one of the store’s shopping carts on a hunt for treasures.
Each day, clerks bring out 7,000 new items, and veteran（老练的）shoppers rush to paw over them. You can find everything from precious jewels to hockey sticks, best-selling novels, leather jackets, tape recorders, surfboards, even half -used tubes of toothpaste.
The store’s own laundry washes or cleans all the clothes found in luggage, then sells them. The Unclaimed Baggage Center has found guns, illegal drugs and even a live rattlesnake.
The store has a little museum where some of its most unusual acquisitions（获得物） have been preserved. They include highland bagpipes, a burial mask from an Egyptian pharaoh's tomb, and a medieval suit of armor.
Statistics indicate that less than one-half of one percent of luggage checked on U.S. carriers is permanently lost and available to the store.
1. Paragraph1 shows that many passengers lose their luggage because______.
A. they are forgetful
B. they are in a hurry
C. there is no lost and found office in many airports
D. the owners of some luggage can’t be identified
2. The reason why the airlines cannot sell the bags is that ______.
A. they have to find the owners
B. they are likely to make a profit on the bags on purpose
C. some bags are expensive
D. they have to keep the bags as long as possible
3.The Unclaimed Baggage Center is very popular because______.
A. there's a large variety of goods.
B. all the things there are very cheap.
C. visitors may purchase something undervalued.
D. Visitors will enjoy some amusing activities there.
4.What can we infer from the passage?
A. A little museum will keep all the precious unclaimed baggage.
B. The percentage of passengers who lose their baggage for ever is small.
C. The things in the Unclaimed Baggage Center are articles for daily use.
D. People are not allowed to buy the illegal things in the store.
5.What is the main purpose of the passage?
A. To introduce how the unclaimed baggage in the airports is handled in America.
B. To introduce an attractive place to tourists.
C. To remind passengers of taking care of their baggage.
D. To advise the airlines to find the owners of the unclaimed baggage.
查看答案和解析>>
科目：高中英语 来源：2015届广东省清远市高二下期末英语试卷（解析版） 题型：信息匹配
A.Lion King
It’s a story of nature, love and friendship, all of which appear in one African adventure. See the young lion cub Simba grow up and overcome all the difficulties in order to become king of the jungle.
B. Little Mermaid
Adapted from Anderson’s fairy tale, Little Mermaid takes you into a deep-sea adventure, to see how Ariel sells her beautiful tail and voice for two legs to see her dream prince on land.
C. Jersey Boys
Jersey Boys is a Broadway classic that features four young men going out by themselves who finally rise up to become movie stars. Come and see more about the struggles and successes of these four young men.
D. Mary Poppins
It is a story of a magic nanny who comes flying in with her umbrella to work for a rather unhappy family with the most naughty kids and shows them what life is all about. Mary Poppins and the Bands family face some challenges and amusing moments.
E. Mama Mia
Mamma Mia is about Sophie’s wedding. It is a great combination of life lessons and laughter. Throw yourself in an 80’s disco theme and Mamma Mia will leave you singing and dancing out of the theater.
F. Stomp (the name of a band)
Come and enjoy a high-energy percussive symphony, coupled with dance, and played entirely on unusual instruments, such as buckets, brooms and sticks. Music is made through the use of everyday objects in a non-traditional way.
下面是观众的介绍，请把观众的介绍和适合他们的节目信息匹配起来。
1.Todd is a DJ in college. In everyone’s mind, he does it quite well. He can always find the proper music to satisfy students’ needs. But secretly Todd always wants to find a new and special way to create music. He hates all kinds of tradition.
2.Friday finally comes. After a whole week of work, Brian just wants to relax, and have some entertainment that can make him laugh. He likes the music in the 80’s and the story of love and marriage, from which he can learn lessons.
3.Ann is a quiet girl. Her most enjoyable moment is when her dad reads her fairy tales. Dad bought her a lot of books. But her favorite is Anderson’s. A lot of stories are sad, making her shed tears. But she loves them. They are so beautiful.
4.Dan is a big fan of animals. He always asks his mom to buy him all kinds of animal books, CDs and Discovery programs or other animal films. This time his mom wants to take him to the theater to see a play, from which Dan can learn to be strong.
5.Tim and Tom are twins. They are famous “bad” brothers in their class and a headache to their mom. Someone suggests that making peer（同龄人）examples for them may be helpful, like in the movies, dramas and so on.
查看答案和解析>>
科目：高中英语 来源：2015届广东省深圳市高三上学期第一次五校联考英语试卷（解析版） 题型：书面表达
Many students fail to perform well in an exam not because they lack ability, but because of the unique pressure of the exam room—the tense atmosphere, the ticking clock on the wall, the teacher walking around, and the thought that their future will be decided by the exam.
It’s not just students who will face pressure. Human beings are competitive animals and we decide to evaluate each other, whether in exams, in job interviews or even on romantic dates, so all of us occasionally get nervous. Removing pressure from life is an impossible dream.
However, there are some ways which can help reduce our pressure. It turns out that we are far more likely to overcome the pressure when we are as familiar as possible with the situation we are about to face. Of course, even when we are well-prepared, we may still feel nervous, but at least we will be more equipped to deal with our nervousness than if we have failed to prepare. Furthermore, we may also benefit from reminding ourselves that the big moment is not that big after all from a different perspective. Even a huge exam is not as important as a loving family, or good health.
【写作内容】
1. 以约30个词概括这段短文的内容；
2. 然后以约120个词谈谈你对“压力”的看法， 内容包括：
（1）正确面对压力的重要性;
（2）作为高三的学生，你通常面临哪些压力？
（3）你在生活和学习中应对压力的措施。
【写作要求】
1、在作文中可以使用自己亲身的经历或虚构的故事，也可以参照阅读材料的内容，但不得直接引用原文中的句子；
2、作文中不能出现真实姓名和学校名称。
【评分标准】
概括准确，语言规范，内容合适，篇章连贯。
查看答案和解析>>
科目：高中英语 来源：2015届广东省汕头市高二下期末英语试卷（解析版） 题型：信息匹配
假如你叫李华，现正在美国加利福尼亚州上大学，你的一个朋友刘英写信向你了解美国加利福尼亚州的情况，请根据以下内容提示给他回信简介加利福尼亚州。
地理方面 | 面积42.4万平方千米，美国西部，西濒太平洋，美国面积第三大的州 |
人口方面 | 约38,000,000人； 据说15000前印第安人首先进入；16世纪欧洲人开始进入；19世纪中世界各地的人带着发财梦进入；未来将还会有人因喜爱加州的气候和生活方式进入。 |
语言方面 | 58% 的人把英语作为母语来讲，42%的人讲其它语言。 |
加利福尼亚州： California；太平洋：the Pacific；印第安人：Indians
【写作内容】
请根据以上内容给朋友写回信，内容包括：
1、加里福尼亚的地理方面的信息;
2、人口及其语言方面的信息;
3、信的开头和结尾已经给出，不计入句子数。
【写作要求】
只能用5个句子表达全部内容。
【评分标准】
句子结构准确，信息内容完整，篇章连贯。
Dear Liu Ying,
Your letter reached me yesterday. You would like me to tell you something about California, so now I am writing to you.
If you want to know more, you may go to https://en.wikipedia.org/wiki/California#History.
Best wishes to you.
Yours ever,
Li Hua
查看答案和解析>>
科目：高中英语 来源：2015届广东省汕头市高二下学期期中考试英语卷（解析版） 题型：书面表达
阅读下面的短文, 然后按照要求写一篇150词左右的英语短文。
In 1882 a baby girl caught a fever that was so fierce that she nearly died. She survived but the fever left its mark ― she could no longer see or hear. Because she could not hear, she also found it very difficult to speak. So how did this child, blinded and deafened at 19 months old, grow up to become a world-famous author and public speaker?
The fever cut her off from the outside world, depriving her of sight and sound. It was as if she had been thrown into a dark prison cell from which there could be no release. Luckily Helen was not someone who gave up easily. Soon she began to explore the world by usin
g her other senses.
Just before her seventh birthday, the family hired a private tutor ― Anne Sullivan. Anne was careful to teach Helen especially those subjects in which she was interested.
Helen proved to be a remarkable scholar, graduating with honours from Radcliffe College in 1904. She had phenomenal powers of concentration and memory, as well as a dogged determination to succeed. While she was still at college she wrote “The Story of My Life”. This was an immediate success and earned her enough money to buy her own house.
She toured the country, giving lecture after lecture. Many books were written about her and several plays and films were made about her life. Eventually she became so famous that she was invited abroad and received many honours from foreign universities and monarchs. In 1932 she became a vice-president of the Royal National Institute for the Blind in the United Kingdom.
【写作内容】
1. 概括短文的内容要点, 该部分的字数大约30词;
2. 就“残疾人需要我们的关心”这个主题发表你的看法, 至少包含以下的内容要点, 该部分的大约120词:
a) 以你认识或了解的残疾人为例, 简述残疾人面临的困难及其取得的成就;
b) 举例说明人们是怎样关心和帮助残疾人的, 还存在哪些不足之处;
c) 呼吁大家都来关心和帮助残疾人。
【写作要求】
可以使用实例或其它论述方法支持你的论点，也可以参照阅读材料的内容，但不得直接引用原文中的句子。
【评分标准】
概括准确、语言规范、内容合适，篇章连贯。
查看答案和解析>>
科目：高中英语 来源：2015届广东省高三暑假联考英语试卷（解析版） 题型：完型填空
As a general rule, all forms of activity lead to boredom when they are performed on a routine(常规)basis. As a matter of fact, we can see this at work in people of all ages. For example, on Christmas morning, children are about playing with their new toys. But their soon wears off and by January those same toys can be found put away in the basement. The world is full of stamp albums and unfinished models, each standing as a monument to someone’s interest. When parents bring home a pet, their child bathes it and brushes its fur. Within a time, however, the burden of caring for the animal is handed over to the parents. Adolescents enter high school with great excitement but are soon looking forward to . The same is true of the young adults going to college. And then, how many , who now complain about the long drives to work, drove for hours at a time when they first their driver’s license ? Before people retire, they usually to do a lot of things, which they never had time to do while working. But soon after retirement, the golfing, the fishing, the reading and all of the other pastimes (消遣) become as boring as the jobs they . And, like the children in January, they go searching for “new ” .
1.A. principle B. habit C. weakness D. power
2.A. surprised B. moved C. excited D. satisfied
3.A. confidence B. interestC. anxiety D. sorrow
4.A. well-organizedB. colorfully-printed C. newly- collected D. half-filled
5.A. missingB. passingC. developingD. falling
6.A. silently B. impatientlyC. gladlyD. worriedly
7.A. interestingB. short C. long D. boring
8.A. graduation B. independence C. responsibilityD. success
9.A. childrenB. students C. adults D. retirees
10.A. carefully B. eagerly C. nervously D. bravely
11.A. requiredB. obtained C. noticed D. discovered
12.A. needB. learn C. start D. plan
13.A. great B. strong C. difficult D. correct
14.A. lostB. chose C. left D. quit
15.A. pets B. toys C. friends D. colleagues
查看答案和解析>>
科目：高中英语 来源：2015届山西省忻州市高三上学期第一次四校联考英语试卷（解析版） 题型：信息匹配
Worry problems are everywhere in our daily life. How to solve them? The answer is that we must equip ourselves to deal with different kinds of worries by learning the three basic steps of problem analysis. The three steps are:
Get the facts
Why is it so important to get the facts? Unless you have the facts, you can’t possibly attempt to solve your problem intelligently. Without the facts, all you can do is wondering around in confusion. It is not an easy job to get facts. When you are worried, your emotions are riding high. 1. .
When trying to get the facts, you can pretend that you are collecting this information not for yourself but for some other person. 2. You can also pretend that you are a lawyer preparing to agree. Try to get all the facts both on your side and the other side of the case. You will generally find the truth lies somewhere in between.
3.
Whenever you are worried, write down the questions that make you worry. And write out all the various steps you could take and then the probable consequences of each step. For example, what am I worrying about? What can I do about it? Here is what I’m going to do about it. After carefully weighing all the facts, you can calmly come to a decision.
Act on that decision.
4. How can you break the worry habit before it breaks you? Crowd worry out of your mind by keeping busy. Plenty of action is one of the best ways to cure worry. 5. If you know a situation is beyond your power, say to yourself: “ It is so; it can’t be otherwise.” Don’t permit little things to ruin your happiness. Try to cultivate a mental attitude that will bring you peace and happiness.
A. Accept what can’t be avoided.
B. Analyze the facts.
C. There comes a time when you must decide and never look back.
D. But here are two ideas that can help you see the facts in a clear and objective way.
E. Unless you take your action, all your face-finding and analysis is a sheer waste of energy.
F. Decide how much anxiety a thing may be worth.
G. This will help you to take a cold and fair view of the evidence.
查看答案和解析>>
湖北省互联网违法和不良信息举报平台 | 网上有害信息举报专区 | 电信诈骗举报专区 | 涉历史虚无主义有害信息举报专区 | 涉企侵权举报专区
违法和不良信息举报电话：027-86699610 举报邮箱：58377363@163.com
