科普类 知识点题库

    Canada is one of the few1in the world to have two official languages：English and French. There are 10 provinces（省）in the country but only one of these-Quebec（魁北克）is known as "French Canada". This is because it was founded by French explorers while British CANADA adventurers discovered and governed the rest.

    Canada left the British empire in 1867 to become an independent country，and English and French have been recognized as the official language ever since. Most people speak English as their first language and the two2television networks broadcast in English throughout the country. Apart from in Quebec and a few places on the east coast，French television is very rare.

    The same goes3traffic signs and menus，for example，outside of Quebec，there are only a few places where you'll see traffic signs in French. And in restaurants. it's4impossible to find French on the menu unless you are in the heartland of French Canada. However，all products sold in Canada must，5 law，have labels and instructions in both languages.

    In Canada's English-speaking provinces，official bilingualism（双语）means that students can6to complete a special French course. In this program，they are taught most of their subjects in French.

    Have you ever had dreams about building a robot? Or putting together a spaceship? Or even seeing your face made out of chocolate? All you need is a 3-D printer!

    The possibilities of 3-D printing seem endless. All the user has to do is to design an object on the computer and choose a material to print in. The printers print in hundreds of different materials including glass, sugar and even skin! When the user presses "print", the 3-D printer spreads the material layer (层) by layer and like magic the object is produced.

    The first 3-D printer was invented in 1986 by an American, Charles Hull. But 3-D printing has only become cheap enough recently for most people to use.

    Designers now use 3-D printing to create unusual things. The Dutch artist Dirk Vander Kooj prints furniture made from old fridges. And doctors have used 3-D printing to print human body parts! The Telegraph reported in February that scientists from Cornell Medical College even printed a man-made ear.

    But like a lot of new technologies, if 3-D printing gets into the wrong hands, it can be dangerous. In 2011 a group of four men in the US used 3-D printing to produce ATM skimmers (提款机盗刷器). These were placed on an ATM and stole over $ 400,000 from users of the ATM. It is terrible to think that criminals like them might one day use a 3-D printer to print a gun.

    But for better or for worse, 3-D printing has been put into use. In a few years, you'll probably be wondering how you could ever live without your 3-D printer!

     Maybe your maths teacher has already taught you how to find the centre of a circle (圆).It isn't easy to learn and it takes some time to do so. Here's a simple idea. This idea can be easily learned in a few minutes.

    Put a corner of a square piece of paper on the circumference (圆周) of a given circle, and you'll see the two sides of the piece of paper meet the circle. And then you'll get two points on the circumference. You may name them Point A and Point A. You may be sure that points A and B are the two ends of the diameter (直径).Draw a straight line through the two points A and B. Then do the same thing a second time in a different place to get another diameter. You'll find the centre at once: the two lines cross at a point and this point is just the centre of the circle.

    How about trying to see if it is easy to learn and remember this simple idea of finding the centre of a circle?

Spuddles are small funny creatures (生物) shaped (形状) like potatoes. They have one very sfeatures (特点): every time a baby spuddle is born, depending on what colour it is, the baby's parents grow a new arm of that scolour. That arm is the one the parents will use to look after that b.

One day a blue baby spuddle was born, b its parents didn't grow a blue arm. How could the parents care for their blue baby? They o had the green arm they had used for his elder sister.

The parents didn't know what to do, and they were afraid that their baby might d  because they couldn't look after him. But the green brother and the pink sister went to their parents and oto share their special arms! The parents were happy. And from that day on t loved their generous (大方的) elder children even more.

And so much did they love their children, and so kind had the little green and pink spuddles been that the two children esoon grew an amazing multicoloured (彩色的) arm, which they could use to htheir parents care for the baby whenever they wanted.

Mouth is an important part of our body. When we eat food, talk with others, sing and smile, we use our mouth. Also, when learning English, we can find the word "mouth" in many sentences.

In everyday life, if someone says something bad about us, we can say "Do not bad mouth me" to talk back. Sometimes, if we say bad things that make others feel sad, we can say, "Sorry, I really put my foot in my mouth this time." We can also use "I am down in the mouth" to tell others our unhappiness. Sometimes when we talk with a friend and we have the same ideas with him, we can say, "You take the words right out of my mouth!" If some people have lots of money because of their rich families, in English, we can say, "They were born with a silver spoon in mouth." But a person who lives "from hand to mouth" is very poor and only has money to buy some cheapest things in need.

From the above examples, we can see that even the same English word can be used in different situations (情形)to tell others different feelings. English is a great language, isn't it?

    The Ministry of Industry and Information Technology has issued(颁发)commercial licenses(商用许可证) for 5G on June 6,2019,according to China Central Television.

    Four major telecom carriers(电信运营商)- China Telecom, China Mobile， China Unicom and China Broadcasting Network-received the first batch of four 5G commercial licenses, said the report.

In May, Chinese companies own more than 30 percent of all essential patents(专利)relate to international standards for 5G, according to China Daily report.

The next-generation technology is expected to be at least 10 times faster than 4G, and its huge capacity(容量)to connect things will enable smart factories, self-driving vehicles and other ways, the report said.

China's big three telecom carriers are forecast(预计)to spend $134 billion to $223 billion) in total on 5G network construction(建设) from 2020 to 2025, according to a report from the China Academy of Information and Communications Technology.

China is set to become the world's largest 5G market by 2025, with 460 million 5G users, according to a forecast by the Global System for Mobile Communications Association, an industry group.

A kind of little cars may take the place of today's big ones many years later. If everyone drives such cars in the future, there will be less pollution in the air. There will also be more space for parking in cities, and the streets will be less crowded.

The little cars of the future will cost less. Driving will be safer, too, since these little cars can go only 65 kilometers an hour. The cars of the future will be fine for going around a city, but they will not be useful for a long way. Little cars will go 450 kilometers before they need to stop for more gasoline (汽油). If big cars are still used with the small ones, two kinds of roads will be needed in the future. Some roads will be needed for the big, faster cars and other roads will be needed for the small, slower ones.

    "What's the name of the supermarket? I can't remember right now." Have you ever heard your grandparents ask questions like this sometimes? Usually, we think that older people's memory becomes bad because their brains get weak. But now a team of scientists at the University of Tubingen in Germany has a new idea. "The human brain works slower in old age," says Michael Ramscar, the team's lead scientist, "only because it has stored more information over time." The findings are based on a series of computer tests related to learning and memory.

Scientists had the computers read a certain amount of words and learn new things each day. When the computer "read" a small amount of data（数据），its performance on cognitive（认知）tests was similar to that of a young adult . But if the computer took in larger amounts of data, its performance was similar to that of an older adult. Often it was slower, but not because its processing ability had dropped. Rather, increased "experience" had caused the computer's database to grow, giving it more data to process-which takes more time. This is similar to how old people process information.

Imagine that one person knows just two people's birthdays and can get them right each time he or she is asked. Another person knows the birthdays of 2,000 people, but can only match the right person to the right birthday 9 times out of 10. Can you say the first person has a better memory than the second person?

"The larger the library you have in your head, the longer it usually takes to find a particular word," Benedict Carey, a science reporter for The New York Times, wrote in an article about the study.

①Animal behavior (行为) is an interesting and attractive study. Scientists research the ways animals use to look for food. They study how animals protect themselves from their predators, and which animals kill other animals for food. All of this helps us understand how useful animals can be.

②Each country or culture raises some animals for food. In the United States, people mainly eat meat from cows, chickens and pigs. In other countries, people might raise sheep or buffalo for meat. These differences come in part from weather and other environmental conditions, People around the world eat all kinds of fish and shellfish from oceans and rivers. In some countries, people don't always choose some animal groups, such as dogs, for food while in other countries such animals may become people's favorite food.

③ In West Africa, animals provide humans with more than food. They have been helping people do daily work for thousands of years. Horses, oxen, and other work animals pull heavy things. Elephants; camels; and other animals carry people and things from place to place. Carrier pigeons (信鸽) have been used to send messages.

④People also receive health benefits' (利益) from animals. For example, dogs and cats can help calm people down. This is helpful for people fighting illnesses. Animals can also reduce stress, helping people to draw their attention to learning new information, such as reading. When people are walking their dogs or horses, it encourages exercise.

⑤Animals and humans share space on Earth, so keeping a healthy relationship with animals, around us is in our best interest.

You may think of museums as dusty collections of old objects, but modern museums are different. They are landmarks and showcases of local culture, offering visitors insights (洞悉) into the past.

The National Museum of Qatar, which opened on March 28, 2019, is the latest example.

The building's interlocking structure of steel, glass and fiber concrete makes people think of the petals (花瓣) of a desert rose. These "roses" are actually crystallized (结晶的) sand, found just under the desert's surface. "It's surprisingly complex and poetic," the designer Nouvel told UK-based design magazine Dezeen.

This pioneering design also makes the building energy -efficient. They form a sunscreen and cast (投射) protective shadows when the sun hits the building from east or west. "I want to build a structure that keeps in line with the condition of the place, to ensure that it offers maximum (最大化的) protection from the sun and save energy," Nouvel said.

Apart from its unique shape, the museum also includes Qatar' s tradition of both nomads (游牧民) and fishermen. It's committed to preserving and showing the wooden dhows (阿拉伯三角帆船) that were once Doha's lifeblood. These boats enabled fishing, trading and the collection of precious pearls. And visitors can see over 1.5 million of them on the hand-embroidered Pearl Carpet of Baroda, the most extravagant (奢侈的) carpet ever, in the museum.

The museum also seeks to redefine(重新定义) the role of cultural institutions. It's hoped that visitors will not only observe the exhibitions but also immerse (沉浸) themselves in Qatar's history. For this purpose，it features a multilayered , 360-degree environment. For example, on the path to the Gallery of Life in Qatar， viewers see open markets, camels carrying goods, and wealthy pearl traders drinking tea and doing business.

"It creates a dialogue between the past and the future," according to a museum press release. "The scheme will give voice to Qatar's heritage (遗产) while celebrating its future."

Recently, as more students use computers for a long time to have online lessons, more of them are feeling eyestrain(眼睛疲劳) Just a few hours in front of a computer screen can make a person's eyes feel tired and painful. A lot of eye doctors have studied this problem and have found ways to solve it. Following their advice will help keep computer users more comfortable.

★Lighting

The light in a room shouldn't be brighter than the computer screen itself. Maybe in many students' rooms, however, the lights are far brighter than they should be. Students can block some of this light by wearing baseball caps to protect their eyes.

★The Screen

A special computer screen which has less bright light should be used, because bright light is especially bad for the eyes. Another problem is to avoid the wrong kind of contrast (对比). Many people think that having light letters on a dark background can cause less eyestrain, but they are wrong. In fact, it is best to have dark letters on a light background.

★Angle (角度) of looking at the computer screen

Students should sit in front of the computers so that they are looking down at the computer screens. The top of the monitor(显示器) should not be so high as the top of a student 's head.

Breaks and Blinks (眨眼)

If students spend a long time in front of a computer screen, it can cause eyestrain. Students should take a break by looking away from the screen every fifteen or twenty minutes. During that time they should either close their eyes or look at things far away. Students should remember to open and close the eyes often while in front of the screen.

    On December 17, 2020, China's Chang'e-5 safely returned to the earth. It brought back the country's first samples(样品) of  (岩石) and soil it had collected from the moon.

Behind the  (成功) of the moon mission(任务) was a team of great scientists. One of them is a young woman named Zhou Chengyu. 24-year-old Zhou has become both the  (年轻的) and the first female space commander at the Wenchang Spacecraft Launch Site in Hainan Province.

Zhou's colleagues often call her "Big Sister." That's a sign of  (尊重) for her. She has now taken part in five space missions. All of them  (需要；要求) the highest level of professional knowledge. For the launch of Chang'e-5, Zhou was in charge of the rocket connector  (系统). This was one of the most important roles in the mission.

The Chang'e-5 mission was named after the Chinese moon goddess. Therefore, many people found it fitting that a strong female figure had  (获得) international attention. They have spoken highly of Zhou's achievements, regarding her as a role model for Chinese girls to look up to.

However, the young commander has shown no  (兴趣) in fame. In fact. Zhou has  (拒绝) many requests for interviews. She feels that they will only get in the way of her work.

Zhou's story gives an encouraging  (启示): Girls are just as capable as boys in science or aerospace. They can do whatever boys can do.

①Chemistry is everywhere in our daily life. Sometimes it's easy to see. At other times, it can be very hard to see the everyday chemistry at work, but nearly everything you touch has some chemicals(化学物质) in it.

②Chemistry helps to make products for use. Something as simple as toothpaste has at least three chemicals that keep your teeth clean. Other things in your daily life are created by chemistry, such as hair products and soap. Without chemistry, we would never have known that we need soap to get the oil out of clothes.

③Chemistry also helps us understand the world around us. Thanks to chemistry, we know bleach (漂白剂)can't be mixed with vinegar(醋), because the mixture can produce harmful gas.

④Chemistry plays a big role in food preparation. Cooking food causes it to go through a chemical change. That is why cooked food often tastes different from uncooked food. Too much or too little of any chemical material makes a difference to the result of baking(烘焙). For example, the cake can be too soft or too hard.

⑤Chemistry isn't something that just lives in a laboratory, it's something that you meet hundreds of times in life. Knowing how chemistry works will give you a greater understanding of the life.

We like to believe that before we make a decision, most of the time, we take time to consider all the facts carefully. However, Experts believe that only 5 % of our decisions are based on a rational(理性的) thought process. So, what influences our decision-making process?

We often leave decision-making to our instincts(本能). Scientists have found out that if we had the choice, we like to avoid pain rather than get something. In fact, we're twice as happy when we try to avoid a bad situation than when we experience a good one. This is why when companies send ads, they use phrases like "How to avoid…", "Don't miss out!", etc.

There are also physical reasons that affect our decision-making. Psychologist (心理学家)John Bargh carried on an experiment where people were asked what they thought of a fictional person, while holding a cold or a hot cup of coffee. Those holding the hot cup believed the person to be warmer and more sociable than those holding the cold cup. So, when temperatures rise, the more likely we are to believe in strangers.

Stress is another thing which affects our decisions. Different situations are more or less stressful for different people. Researchers have found, though, that women are more conservative(保守的)about decisions when stressed, while men are to make riskier choices.

It may come as a surprise but every day from the minute we get up, we have to make countless decisions, like what to wear, what coffee to have and so on. Each choice makes our brain a little bit more tired, and this affects our decision-making. That's why important people, like presidents wear the same three suits all the time, wanting to limit the small choices and spend more brain power on the bigger ones.

In a small village, there is a house with 1, 000 mirrors(镜子).

A little dog learns about this place and plans to visit it one day. When he gets there, he is very happy and goes into the house. He looks into the mirrors with his ears up high and his tail wagging as fast as it can. It is strange for him to see 1, 000 other happy little dogs with their tails wagging just as fast as his. He smiles and 1, 000 great smiles smile back to him, they are warm and nice. As he leaves the house, he thinks to himself, "This is a good place. I will come back and visit it often. "

In this same village, there is another little dog who often gets angry. The dog wants to visit the house too. He goes into the house with his head down. When he sees 1, 000 angry dogs looking back at him, he growls at them and is afraid to see 1, 000 little dogs growling back at him. As he leaves, he thinks to himself:" What a terrible place. I will never go back there again. "

Mirrors can't change, but faces can. What kind of face do you have today?

The erhu is a traditional Chinese musical instrument. It is the most popular of the huqin family. In the Song Dynasty, musicians began to use this type of huqin to perform different kinds of music, and it became quite a popular instrument. With the rise of some forms of folk art, the art of the erhu developed quickly during the Ming and Qing Dynasties. It became an important accompanying (伴奏) instrument in different folk music. Now it is used in both traditional and modern music. It has even become a solo (独奏的) instrument. One of the most famous musical pieces played on the erhu is Erquan Yingyue by Abing.

The erhu used to be mainly played by common people, As the playing skills were passed down by oral (口传) tradition, there are few written records about the erhu that can be found. To study the history and the development of the erhu, historians usually turn to ancient paintings, sculptures and murals (雕塑和璧画). The earliest pictures of this instrument were found in Yulin Caves and Eastern Thousand Buddha Caves in Gansu Province.

Because of so many people's effort, the erhu becomes more and more popular around the world. In fact, we can hear the familiar sound of the erhu in many Hollywood productions, such as Kungfu Panda in 2012 and most recently, the Oscar nominated(提名)film Up in the Air(《在云端》). When people watch these movies, they also enjoy the special music of the erhu. The erhu is also called "Chinese violin" by many westerners, but in many ways, they are quite different.

Tea and coffee are two of the most popular drinks in the world. However, people usually like one more than the other. These drinks also have very different uses.

Tea drinking started in China over 4,000 years ago. Tea is made from leaves. These days, some people drink tea for health, using it to help with stress(压力) or losing weight. However, most people in tea-drinking countries think of tea as more than just a healthy drink. In fact, tea drinking in some countries is a part of the culture. In Turkey(土耳其), tea is always there when people meet. Whether in someone's home or a company, tea is always offered as a way of welcoming. In the UK, homes and offices usually have tea time. Tea and other dishes are served at tea time in the afternoon. It is a way of relaxing with friends or co-workers(同事).

Coffee came much later than tea, just over 1,000 years ago. Coffee is made from beans. Something in the coffee beans makes a person feel active. Most people do not drink coffee to relax. Instead, they drink coffee to get going. Many people drink coffee in the morning to help them wake up. Others will also drink coffee during short breaks in the afternoon to keep going through the working day. Some people may visit coffee shops just to meet and talk with friends. However, many people in coffee shops drink coffee while working on their computers.

Is tea or coffee more common in your country? Between the two, which do you like to drink more?

Dogs are the best pets of humans. They come in all sizes. Some dogs are as small as a football, and others are as tall as a desk. Dogs' fur(毛) is different, too. It can be long and soft, or smooth and hard. People don't mind the kind of fur, because all dogs are good to hug.

Dogs need to be taken care of. Short-haired dogs are the easiest to look after. But all dogs need a bath once in a while. Giving a dog a bath is a lot of fun. After you give a bath to your dog, it shakes the water off its body. Be careful, or you will get wet!

Dogs like to make their owners(主人) happy, so dogs are easy to train. They can follow simple orders.

Dogs are really amazing animals. Some dogs pull sleds(雪橇) across icy places. Some save people who fall into the river. Other dogs do tricks(表演绝技) in movies. A dog has even flown in a rocket(火箭) to space.

Why not keep a dog as a pet?

Each year the number of cars on roads and streets is becoming larger and larger. Millions of new cars are produced. One out of every six Americans works at putting together the parts of cars, driving trucks, building roads or filling cars with gas. Americans won't live without cars!

Most Americans find it hard to think what life would be without a car. However, some have realised the serious problem of air pollution caused by cars. The polluted air is poisonous and dangerous to health.

One way to reduce the polluted air is to build a new kind of car. Some large car factories are trying to do. But to build a clean car is easier said than done. It develops very slowly.

Another way is to take the place of the car engine (发动机) by something else. Engineers are now working on some new cars. It will take years to develop it.

To prevent the world from being polluted by cars, we'll have to make some changes in the way of life. Americans, for example, have to cut down the number of their cars. They are encouraged to travel and go to work by bike. Riding a bike is thought to help keep the air clean.

But this change does not come easily. A large number of workers may find themselves without jobs if a car factory closes down. And the problem of air pollution would become less important than that of unemployment (失业).

Although cars have brought us a better life, they have also brought us new problems.