科普类 知识点题库

    When IDr. Karen McComb came to Amboseli Park, her first task was to learn the names of the one hundred or so elephants most often seen.

    Scientists working in the park have learned to study elephants by watching them up close. They have a list of almost one thousand elephants. There are records for all of the elephants born since 1972. Amboseli was a good place for Dr. McComb to study animal communication. Elephants were a great subject because their lifestyle depends on communication.

    Dr. McComb and her team had learned a lot about elephant communication, but they kept on thinking about one puzzling watch. Some families were better at distinguishing calls of friends from those of strangers.

    What made some families smarter than others? The scientists searched their records for an explanation. To their surprise, there was only one factor of importance: The "smartest" families always had the oldest grandmothers. A family, as it did in all other activities, waited for some signal from the grandmother when they heard a strange contact call. And older, more experienced grandmothers were better at telling whether other elephants were strangers or friends just by their calls.

    That was an important discovery. It showed how an elephant family depends on the experience of the grandmother.

These days, cars are designed using computers. Let's look at how a new car is created.

First, several 1 talk about the new car and any good ideas that they have. Then they sit down at their computers and 2 many sketches. The best two or three drawings are chosen and then more detailed drawings of the 3 are developed on the computer. You can change the size, shape or color of any part on the computer to see how the car would look and then you can 4 the best design.

Both the inside and the outside of the car have to be designed. Part of the inside of the car is5so that the designers can sit in it. They can feel if there is enough 6 inside and if they can7everything. Then some cars are built-there are more than 15, 000 parts of a car to 8.

When everything is known to be 9 the cars are made in the factory. Again, computers are used to make sure that all the parts are 10 as they are needed. The factory usually stays open all through the night so that the car production never stops.

Do you want to know something about the history of weather? Don't look at the sky. Don't look for old weather reports. Looking at tree rings is more important. Correct weather reports date back only one century, but some trees can provide an exact record of the weather even further back.

It is natural that a tree would grow best in a climate with plenty of sunlight and rainfall. It is also expected that little sunlight or rainfall would limit the growth of a tree. The change from a favorable to an unfavorable climate can be determined by reading the pattern of rings in a tree trunk. To find out the weather of ten years ago, count the rings of a tree trunk from the outside to the inside. If the tenth ring is far from the other rings, then it is certain that plenty of sunny and rainy weather occurred. If the rings are close together, then the climate was bad for the tree.

Studying tree rings is important not only for the history of weather, but also for the history of man. In a region of New Mexico you can find only sand--no trees and no people. However, many centuries ago a large population lived there. They left suddenly. Why?

A scientist studied patterns of dead tree rings which had grown there. He decided that the people had to leave because they had cut down all the trees. Trees were necessary to make fires and buildings. So, after the people destroyed the trees, they had to move.

In this instance studying tree rings uncovered an exciting fact about the history of man.

    Dogs can be good friends for people. They can also be in !

    Well, the US held the 140th Westminster Kennel Club Dog Show (威斯敏斯特全犬种大赛) in New York City. This is sporting event in the US.

    To take part in this show, a dog must be 100 percent one kind of breed (品种) .

    On the day of the show, owners to make their dogs look good. Then, they show their dogs to the audience (观众) and judges (裁判) . Judges are : how dogs act, their fur (毛发) and more.

    To be in dog shows like this, it costs around $50,000 to $100,000a year. So why do people do it?

    Some do it to teach people about dog breeds, while others want . But they must love their dogs a lot because they spend so much time and money on them.

    Can trees talk? Yes—but not in words. Scientists have reasons to believe that trees do communicate with each other. Not long ago, researchers learned some surprising things. First a willow tree (柳树) attacked in the woods by caterpillars (毛毛虫) changed the chemistry of its leaves and made them tasteless so that the caterpillars got tired of the leaves and stopped eating them. And the tree sent out a special vapor—a signal causing its neighbors to change the chemistry of their own leaves and make themselves taste also terrible too.

    Talking, of course, doesn't need to be always in words. We can talk to each other by smiling, raising our shoulders and moving our hands. We know that birds use a whole vocabulary of songs, sounds and movements. Bees dance their signals, flying in certain patterns that tell other bees where to find nectar (花蜜) for honey. So why shouldn't trees have ways of sending messages?

    Beauty sleep is a real thing, researches have shown that people who have enough sleep look more attractive (有魅力的) to others.

    A few bad nights are enough to make a person look especially "more ugly", their sleep experiments show.

    The researchers asked 25 university students to join in their sleep experiment. They were asked to get a good night's sleep for two nights.

    A week later, they were asked to sleep for only four hour every night for two nights in a row. The researchers took make—up free (素颜) photos of the volunteers after both the good and the bad sleep.

    Next, they asked 122 strangers to have a look at the photos and judge (评价) them on attractiveness, health, and sleepiness, as well as asking them: "How much would you like to make friends with this person in the picture?"

    The strangers were good at judging whether the person they were looking at was tired, and if he was sleepy, his attractiveness score would be low.

    The strangers also said they wouldn't want to socialize with the tired students. The researchers say this is natural for people. An unhealthy-looking face makes people run away. In other words, people don't want to hang around with people who might be ill.

    Dr Brewer, an expert at the University of Liverpool said: "Judgment of attractiveness is often unconscious (无意识的), but we all do it, and we are able to judge on even something small like whether someone looks tired or unhealthy. This study is a good reminder of how important sleep is to us."

Is there a connection between music and language?

According to recent studies, the answer is yes. Music improves certain language abilities in the brain. Here, let's look at two examples.

A recent study by researcher Kraus shows that playing a musical instrument can improve a person's hearing ability. In his study, two groups of people listened to a person talking in a noisy room. The people in the first group were musicians, while those in the second group had no musical training. The musicians were able to hear the talking person more clearly. Musicians hear better because they learn to pay attention to certain sounds. Think about violinists in an orchestra(交响乐团). When the violinists play with the group, they hear their own instrument and many others, too. But the violinists must concentrate on what they are playing, and pay no attention to the other sounds. In this way, musicians are able to focus on certain sounds, even in a room with lots of noise.

Schlaug, a doctor at Harvard Medical School, works with stroke(中风) patients. Because of their illness, these people cannot say their names, addresses, or other information normally. However, they can still sing. Schlaug was surprised to find that singing words helped his patients to speak. Why does it work? Schlaug isn't sure. Music seems to make different parts of the brain work, including the broken parts. This might help patients to use that part of the brain again. Music improves attention, memory, listening skills, and language abilities. It can even help sick people get better.

Playing an instrument or singing can help us do better in school and keep our brain sharp(敏锐的)a swe get older . Music is not only enjoyable, but also good for us in many other ways.

How do you go to school every day? By bike or on foot? Maybe you can try a new way-taking a S'Cool Bus.

The S'Cool Bus is also called the bike bus. It was invented in the bike kingdom—the Netherlands. It is all about green lifestyle，sport and sharing. It's interesting for kids to ride the bus together to go to school.

Also, it is very safe. The bike bus has a driver and eleven seats for kids. Each one has a helmet(头盔) and safety belt(安全带).There is also a roof on the bus. It can be used on hot days or rainy days to make kids feel comfortable.

Riding the bike bus is one of the greatest ways for children to get to school. Peter, a10-year-old pupil，becomes a big fan of the bike bus. "Now the S'Cool Bus is my favorite way of transport. I can ride it together with other kids to keep healthy. It's full of fun."For most parents, it can help them save a lot of time because they only have to pick up their children after school.

The S'Cool Bus is becoming more and more popular in some countries like Germany and France. Its creator Thomas Tolkamp says, "I hope I can sell the bike bus to more countries in the future. As green lifestyle becomes popular, ideas like this get popular, too. I think it will work well in other countries." The use of S'Cool Bus shows us that we can save the Earth in many ways as long as we want to have a try.

Humans have many organs（器官）, but you can enjoy lots of things because of your ears. Do you know how the ears work?

The ear has three parts: the outer ear（外耳）, the middle ear and the inner ear（内耳）. The outer ear is the part you can see. It collects sounds around you. The sounds then travel down to the middle ear, the inner ear and then to your brain.

Your ears never stop working, even when you are asleep! In other words, your ears continue hearing sounds, but you can't hear the sounds just because your brain ignores them.

But ears do more than hear. They help you keep balanced（平衡的）, too. In the inner ear, there are organs that are filled with liquid（液体）and covered with small hairs. When you move your head, the liquid and hairs move, too. They send messages to your brain about the position of your head.

More surprisingly, ears even help to taste food. Of course, you don't actually taste food with your ears. But there are nerves（神经）running through the middle ear that connect the tongue（舌头） to the brain. If something happens to your ears, you might have a hard time telling different tastes.

The ears are truly important organs. We should protect our ears well.

    The ancient Greek philosopher Plato said, "Music is a moral law. It gives soul to the universe. Wings to the mind, flight to the imagination, and charm and joy to life and to everything."

 Children's brains are developing and their brains are like sponges(海绵) that soak up anything that's going. That means children are much more ready to hear new things than adults. In other words, the more types of music children hear, the more types of music they will like as adults.

 New research shows that offering an interesting environment with music is good for children's health growth and development. Children can learn, understand and think in a logical way if they study music at an early age.

Music improves the ear—and we know that children who have studied music can learn foreign language more easily and pronounce them far better.

 Some children are too shy to take part in activities with others. However, they usually feel relaxed when they join in a music activity.

 Whether they are listening to music, singing along with a song, playing an instrument or dancing to music, they seem totally absorbed in music.

    Let children enjoy the wonderful feelings music brings and make music a pleasant part of their lives!

     Here's what you can do.

    1 Wear masks outdoors.

    Wearing a mask is one of the most effective ways to protect you from getting infected (感染) Make sure to wear it properly by tightening up the nose clip (鼻夹）and palling the bottom of it over your chin (下巴) . 37.

    2 Cover your coughs and sneeze with tissue (纸巾) .

    Cover your mouth and nose with a tissue when you cough or sneeze, or you can cough or sneeze into your sleeve, but avoid covering with your hands directly.

    3

    Wash your hands with soap and running water thoroughly for at least 15 seconds.

    Before eating and after using the toilet.

    After returning home.

    After touching trash or garbage.

    After contacting with animals or handling animal wastes.

    4 Strengthen (增强) your immune system (免疫系统) and exercise regularly.

    Exercise regularly is one of the most important ways to help you stay away from catching any infections.

    Make sure that shared spaces have god air flow and avoid going to crowded places such as hospitals, railway stations and airports.

    Avoid close contact with people who have flu or cold-like symptoms.

    Avoid contact with wild animals or farmed livestock (家畜)  without any protection.

The water on Earth has been moving all the time for billions of years. It travels from ocean to air to land and back to the ocean. This continuous movement is called the water cycle, and it is the reason that earth has the same amount of water today as it did back in the days of the dinosaurs. The water cycle provides people, animals, and plants with life-giving water. Each stage of the water cycle is equally important. Here are some of the stages.

Evaporation is the stage of the water cycle when water moves into the air. Water in oceans, seas, lakes, rivers, and streams is in liquid form. The sun's radiation heats the water and causes it to change into vapor. It rises into the atmosphere.Areas that receive more heat from the sun experience more evaporation.

Condensation is the stage of the water cycle that follows evaporation. In this stage, vapor changes back into liquid while it is still in the air. Vapor in the atmosphere moves to different regions of Earth. When vapor moves to cooler regions, it also cools. Cooling causes vapor to change back into liquid. It turns into many tiny water droplets.The water droplets collect, making them visible in the air. Clouds and fog are collections of water droplets that result from condensation. The water droplets can remain in the air as long as they are light enough for air currents to carry them.

Precipitation occurs after condensation. This is the stage of the water cycle when water travels back to Earth's surface. Water droplets in the atmosphere collect in clouds and become heavy. They become so heavy that air currents can no longer carry them. The droplets fall to Earth's surface as rain. If the air is cold, the water droplets may be snowflakes, hail, or sleet. Some of the precipitation soaks into the ground and some of it goes directly back into the same oceans, seas, lakes, rivers, and streams from which it had evaporated.

Although the water cycle has kept water usable for billions of years, the fresh water that we depend on is limited. It is necessary that we think about ...

Forest

When working on your homework, you might sometimes find that your smart phone is distracting （使分心） you. An app called Forest can help you stay focused. When you set a new task in the app and set a certain amount of time to finish it, a tree seed will be "planted" in the app. If you keep finishing your task, the seed will grow into a tree. But if you close the app and play with your phone, the tree will wither and even die. Once you finish the task, your tree will be "planted" in the app. Gradually, you will have a forest! You can share your achievements with your friends and try to "plant" different kinds of trees.

Rocket Alarm Clock

It's hard to get out of bed every morning. You might hit the "snooze" button（"打盹"按钮） on your alarm clock again and again just to get a little more sleep. However, the Rocket Alarm Clock app can help!

The app's alarm cannot be easily turned off. You have to shake your phone wildly, solve difficult math problems, or even blow into your phone's microphone to turn it off. For example, in one of the app's modes, there are some unidentified flying objects( UFOs) that are attacking（攻击） the earth. You have to blow hard on your microphone to get rid of（摆脱） the UFOs and turn off the alarm.

Xiawen

This app makes reading news feel like chatting with a friend. News stories pop up（弹出） just like a text message from a friend. If you're interested, you can click "read on". If not, just click "new one".

In addition, the app's news stories are shown in an interesting way. There are emojis（表情符号）, audio clips （音频剪辑） and memes（表情包） to help you better understand each piece of news. If you want to comment on the stories you read, you can join different groups and discuss the stories with others.

Most people don't take first aid(急救)training because they are busy. Some even think only doctors need to learn first aid. But in fact, it is useful. Here are the good sides of learning first aid.

First aid helps save lives. Giving someone first aid can help him or her get better fast. First aid training teaches how to keep calm in emergencies (紧急状况下).

Help someone feel better. Not every accident or injury(受伤) needs a visit to the hospital. But it doesn't mean you should not try to help someone injured, even though the injury isn't very serious. You can use first aid to help anyone in need, for example, a person who doesn't feel well because of a fever.

Keep a situation from getting worse. Sometimes, if a person doesn't get first aid in time, his or her situation will get worse soon. If you give him or her simple care, you will help him or her feel better and keep things from getting worse.

Do you play with your phone before bedtime? According to a US study, looking at screens at night can cause us to sleep badly.

In the evening, our bodies make melatonin (褪黑素)，Melatonin helps us feel sleepy and relaxed. It's an important part of our sleep cycle (周期). However, our electronic screens stop that cycle from working normally. That's because phones, computers and TVs make blue light. Blue light stops our bodies from making melatonin. Even just a little bit of blue light can make a difference. Eight minutes of blue light can keep our brain (大脑) "awake”for another hour, according to the study. Even if we fall asleep, we may have lots of dreams. Our brain won't have a good rest.

It's even worse if you play an exciting game before going to bed. Games make our hearts beat faster, so we have a harder time falling asleep. Then, when we fall asleep, we don't get enough "deep sleep". So next day we will feel very tired.

Use these following tips to get a good night's sleep.

★Have a relaxing habit every night. Take a warm shower, or read a book, and then you can relax yourself.

★Sleep in a dark, quiet room and the room is not too warm or too cold. This can help you fall fast asleep.

★Count sheep. It's the oldest way, but it can really work! So if you can't get to sleep, try this one.

★Don't eat a big meal or have caffeine, but you can drink some milk. Don't run around or exercise for three hours before bedtime.

When can you get a phone? The answer is when your parents think you need one. Of course, many kids seem to get a phone at around age 12 or 13 or at an even younger age because their parents think it is helpful. A phone can let the children soon contact (联系)their parents if something goes wrong or they need help. Likewise, it can also make parents quickly contact their kids so that they can check(检查) on them and make sure they're OK.

If you get a phone, work out some rules with your parents. Learn to be in control of your phone. It will cost (花费) you much if you send too many messages or talk too long. Also work out some other things. When can you use your phone? When must you turn off the phone?

If you get a phone, you'll also have to make sure you can take care of this new "friend". Put it in the same place so that it doesn't get lost. And don't use it in the bath-room(洗手间), because it is easy for you to drop your phone into the toilet(厕所).

Facial recognition (脸部识别) cameras are everywhere, including in your smartphone. Many people use this technology to unlock their phones, open doors or pay quickly, but there is a problem – everyone is wearing masks. What a hassle!

Now, the companies have improved their technology. Facial recognition technology can now know people even if they are wearing a mask. Beijing-based tech company Hanwang has announced a software (软件) which can correctly recognize 95 percent of people wearing masks, Engineering & Technology (E&T) reported. What's the secret? It's all about your eyes. Marios Savvides, a professor at Carnegie Mellon University, US, studies facial recognition technology. As we get older, he said, our faces change shape, but not the area around our eyes. It stays the same – even if we put on weight.

Facial recognition software is about more than just unlocking your phone. It's about public safety. For example, you don't need to take an ID card, which can be lost or stolen. It also means that virus (病毒) isn't spread by touching things, said NEC's Shinya Takeshima. "Touchless check has become very important to COVID-19," he said to Reuters. "We hope to do something for safety and peace of mind."

More than that, facial recognition can be used to fight crime. "It can tell criminals and terrorists," said Huang Lei, one of Hanwang's leaders. Hanwang's technology is used by police in high-security (安全等级高的) settings. This means places like government buildings, subway stations and airports. Similar technology is used by the United States Air Force and other governments.

Huang talks about one big weakness of this technology. "It fails when people wear both a mask and sunglasses. In this situation, all of the key facial information is lost," Huang said to E&T. 

DNA is the whole "map" of the human body. It is something that all humans have, and it tells the body what to do. DNA is the reason that we look like our parents, because we get some of the DNA to make our own.

People have been trying to understand the human body for a long time. In 1860, Mr. Mendel discovered why we look similar to other people in our family. It is because of small things called "genes（基因）" in our body. In 1953, two scientists, Watson and Crick, found out that those small parts are real messages. They are written in the DNA with a special language.

In 1961, another two scientists found the first "word" that they could understand in that language. It shows how DNA tells the cell（细胞）to build its parts. So far, scientists have found all the words in the DNA map, but we do not understand what they all do. By understanding what just one "word" means, we can help to save people from several illnesses. So the more we understand, the more doctors will be able to do.

Most people hope that this will help to make better medicine to help sick people. Other people worry that when we learn more "words" and find out more information, we will use in the wrong way, just to make people more attractive（有吸引力的）, or stop sick people getting jobs.

①Would you like to get fewer colds and feel better? Would you like to have a taste of a special plant? Would you like to keep a plant with little care? An Aloe Vera plant could be just what the scientists may suggest!

②Growing Aloe Vera plants at home can make the air clean and fresh. Studies have shown that they give off oxygen (O₂) and take away harmful things from the air. With clean and fresh air, you are more likely to stay away from colds, sore throats and dry coughs. And even if you do get sick, Aloe Vera plants may help you get better from the illness faster.

③Did you know that Aloe Vera plants can be used as medicine? Aloe Vera gel (胶体) helps to deal with the pain of burns. And it also helps with itchiness(痒) caused by insect bites. To get this gel, just cut off a part of the plant, peel it, and put the gel on the affected skin(患处). This easy-to-get and safe-to-use medicine is available to you all year round.

④Apart from medical use, Aloe Vera plants are also popular in food industry. Whether you are interested in Aloe juice or crazy about Aloe yogurt, you'll easily find them in the supermarket. Aloe Vera can also go with other vegetables to make a safe dish on your dinner table.

⑤   ▲    . They like dry, warm air with bright light, so they grow best when placed near a window. Aloe Vera plants are able to keep water in their leaves. So, they do not need to be watered so often as most houseplants. Just wait until the earth is completely dry before you water them. When watering, make sure the earth is wet enough so that it can last for a long time. That's all you need to do to take care of an Aloe Vera plant. Isn't it the perfect plant for lazy and forgetful gardeners?

You fight scary monsters; you live in a house made of chocolate; you don't have to go to school anymore. Where could all of these impossible things happen in my dreams?

A dream is a series of pictures, ideas and emotions playing in the mind during sleep. Humans spend one third of lives sleeping and six years dreaming. A person usually has three to five dreams a night, although one may not remember his or her dreams.

Many dreams, at least the ones we remember, are strange and interesting. That's why most people believe that dreams must have some deep meanings or important messages. However, people in different cultures have different understandings of the same dream.

For example, when dreaming of fire, Chinese people think of money. The Japanese would say it means "trouble". For people in the West, a dream of fire means something new is coming.

Scientists have very different ideas about the deep meaning of dreams. Some believe that a dream is only a normal process of sleep and doesn't tell us anything. Other scientists think that a dream is a direct message from one's mind. Dreams are like a window into one's wish and fears. For example, if you're very nervous about an exam, you may have nightmares of monsters running after you.

Technology also helps us to know more about dreams. In the film Inception, people enter others' minds while they are dreaming. Well, in real life we can do that, too. Scientists can now read people's dreams by scanning their brain activity during sleep. Would you let scientists look into your dreams?