科普类 知识点题库

    It wasn't a long journey, only about 3 miles but the engineers hope to use it for longer. Drones could make these deliveries safer and quicker than other vehicles. As they are unmanned, they might even be cheaper to operate.

    The operation was a  and the patient is now getting better in a hospital in the USA. “This whole thing is amazing,” she said. Drones are already being used  the world to help people and save lives. In Africa, drones are often used to deliver medicine to remote or hard-to-reach places. They've also been used in Australia to help find people caught in  seas and even deliver safety devices to people in danger. As this new technology develops, who knows what other uses we could find for drones?

    A sign is another kind of language. Here are some of them that you see on the roads. Number one is a sign with the number thirty on it. When drivers see this sign, they must not go at a speed of more than thirty kilometres an hour. We see this sign when we are getting near a town.  Number Two is a sign that we see when we're near a crossing. We must drive carefully. Number Three is a sign to say that there is a bend on the road. Again, we must drive slowly and carefully. It is not safe to go round a bend very fast.  Number Four is a sign showing that there is another road corning in from the right. There is a junction(交叉点) at this place. Number Five is a sign showing that there is a hill and Number Six is a sign showing that the road gets narrow. We must go slowly and carefully. Number Seven has the word "SCHOOL" on it. This is a sign to say that there is a school at the side of the street on the road. Perhaps there are children going to or leaving school. So we must look carefully and go slowly. Number Eight is a sign with the letter "P" on it. The letter "P" means "Parking". At some places, there are signs "NO PARKING" or "NO WAITING". If a driver leaves his car near one of these signs, a policeman may come and write down the number of his car.

    Always play in a safe place. A park is a safe place there are no cars or trucks. But do not talk to anyone you do not know. Never go with a stranger into a motor car.

    Before the road, stop and look both ways. Look left. Look right. Look left again.

    Keep from houses or buildings that are being built or knocked down. Something might fall on your head, or you cut yourself by broken glass.

    Medicine or pills can be dangerous. Never swallow any pills or medicine you find in the cupboard.

    Wear a life jacket whenever you go out in a boat. Even if you are not in the open sea, and the water is not deep，you should have your life jacket on. It's easy to fall out of a boat.

    put your head out of a car, bus or train. Many children have been killed by doing this.

Have you ever taken part in a marathon? A marathon is 42km long. It is the longest race in the world. To make the harder training is quite necessary. A runner should start to prepare for a marathon at least three months before. Preparation may have races, many hours of running at different speeds and changes in diet. During the training time the runner must eat a fit diet. The diet should have lots of things needed in training the players.

In the early days of training, runners run 80km per week. The running is increased ever two or three weeks and at least two long runs per week are needed. Two weeks before the marathon, the training programme becomes less, from 100km per week down to 60km and then to 30km in the final week. On the last two days they may not run at all.

Breakfast should be eaten at least three hours before the race. Easily digested (消化), food such as cereal (谷类), toast (烤面包) and scrambled (碎的) eggs is best, with as much fluid (液体) as possible. Runners should drink water about half an hour before the race.

    What is color? Why do some of the things around us look red, some green, others blue? Colors are really made by reflected (反射) light. We see colors because most of things reflect light. Something is red, for it reflects most of the red light. In the same way, if something is green, it reflects most of the green light. If something reflects all light, it is white. Some of the light is reflected and some is taken in (吸收) and turned into heat (热能). The darker the color is, the less light is reflected, and the more light is taken in. So dark-colored clothes are warmer in the sun than light-colored clothes.

    You might have noticed that sometimes, when you are playing mobile games, the picture suddenly freezes (卡顿) because the network speed is o slow. However, these annoying things will soon become a thing of the past, as China just issued commercial licenses (发放商用牌照) or 5G networks on June 6, 2019. This means that China's telecommunications companies will be able to offer 5G network speeds to users.

    The "G" in "5G"stands for generation. IG let us talk to each other, 2G let us send messages, 3G gave us mobile data and internet, and 4G made all of these things faster. So what will SG bring?

    It will allow us to download an entire HD movie in seconds. The delay (延时) between sending and receiving data will be shortened. Now, 4Gtakes about 100 to 200 milliseconds, while humans have a reaction time of about 200 to 300 milliseconds. But 5G will get the delay down to I millisecond or less, which is almost real-time.

    With the development of 5G, new kinds of technology will be created and used.

    Robots will be used to do operations because doctors will be able to control them from somewhere else without any delay. Self-driving cars will be able to drive more safely because they can smoothly communicate with each other, traffic lights and road sensors.

    5G networks will be powerful, but not perfect. They do have some disadvantages.

    On one hand, 5G signals don't go very far. On 4G networks, you can be 10 kilometers away from the nearest transmission base (传送基站) and don't lose signal. But 5G maxes out at about 300 meters. On the other hand, 5G signals have a hard time going through walls and rains. This means we will need to build many small transmitters to make sure 5G signals can be received everywhere. Soon you may see small boxes on every street lamp and building

    When you think of money, you probably think of “cash”(现金). These are the paper notes and metal coins you use to buy things with. The first paper money was invented in China, and has been used for thousands of years. But in the near future, we may not use this type of money anymore. Does this mean the end of money?

    In fact, only a small percentage(百分比) of money is cash. Over 90% of money today exists(存在) inside computers at banks. It is mostly digital, just numbers. We also use cash less and less. Since the credit card was invented in the 1950s, people have used their "plastic" to pay for things more and more. Using a card is quick and easy. You don't have to carry around heavy change and count it. We also do more and more shopping online, so we don't need cash for that.

    In the near future, we probably won't use plastic cards, either. All payments will be digital. We can already use our smartphones to pay. Soon, there will be shops we can walk in, take what we want and walk out，without waiting or counting money. Technology in the shop will know what we take, and just charge（记在账上） the cost to our bank accounts.

    Of course, money will always exist in some forms. People will always need a way to buy and sell things and store their wealth. But the days of cash are numbered. This will make things easier, but it is also a pity. Paper money and coins are nice to look at and they show us something about where we are. It is also true that using cash makes us spend less money, because we feel we are losing something when we spend it. However, when we make plastic or digital payments, we don't feel this, and so spend more.

    Debt is something necessary, but it can be a big problem. Whatever money looks like in the future, we shouldn't spend money we don't have!

Have you ever imagined going to other countries without your paper passport? That will soon come true. And your paper passport will become history. You may use a new kind of passport called "cloud passport" in the future.

It's reported that Australia will be the first country to use the cloud passport. With the cloud passport, you don't have to take a paper passport with you all the time. The cloud passport will have your name, photos and other information. And if you go to other countries, you can just check the information on the computer.

When you take a paper passport with you, you might lose it. But with the cloud passport, you don't have to worry about that.

Do you think the cloud passport it a great idea? Perhaps you will have it in the future, too.

    Scientists think that there has been life on earth for millions of years. However, we haven't found life on other planets yet. The earth is a planet and it goes around the sun. And there are seven other planets that also go around the sun. The sun and its planets are called the solar system. The solar system is a small part of the universe.

    Scientists has launched many spaceships to explore other planets in the solar system. Some spaceships have gone beyond the solar system. However, no one has discovered any life in space yet.

    Why has no one from other planets sent us a message? Have they tried to send information to us? With so many stars in space, are we alone, or is there life on other planets in space?

    Many students think that learning a new language is very difficult. But if your brain (大脑) is only the same size as a bird's, you will know how difficult it is to learn English. That is what some birds can do.

Many birds can copy (模仿) the sounds of language. A type of African parrot is very good at doing this. This kind of parrot has grey feathers and people say they are clever.

Every December in London, the National Cage and Aviary Bird Show tries to find the best "talking" bird in the world. One bird named Prudle stood out (突出) among the " talking birds"  by winning this prize every year from 1965 to 1977. In 1958, somebody took Prudle from his nest in Uganda, and then sold it to a woman named Iris Frost. She then took care of him at her home in Seaford, England. Before he died in 1994, aged 35, Prudle knew almost 800 words in English. Prudle was also the oldest bird in the world that lived in a cage.

Another parrot named Puck was tested in 1993. It turned out that Puck knew even more words than Prudle. Puck knew more than 1,700 English words. In the 2003 Guinness Book of World Records, Puck was listed as knowing more words than any other bird in the world.

Dogs are very sociable(合群的) animals. When owners go out and leave their dogs alone, the dogs get worried and upset. Dogs should be trained(训练) to be on their own while still young instead of when they are older and set in their ways. When owners are not around, they should provide some toys for their dogs to play with. Leaving the radio or television on might also provide relaxing background noise.

Howling(嚎叫) is a form of communication. Dogs do it to tell one another where they are. Some dogs howl when they are lonely, while others do it when greeting strangers whom they are seeing for the first time. Some even howl to music and do this because it is fun.

When it comes to training dogs, giving rewards is a far better way than using punishment. Food makes an excellent reward, and if they do not respond(反应) to this, owners should try touching. Dogs like being touched by owners very much. Words of praise work well too, but not as well as food or touch. It helps if owners spend more time with their dogs.

Smarter than We Thought

    It's a popular belief that fish can't remember anything for longer than seven seconds.

    It may seem sad to think that they don't remember what they've eaten or where they've been, and they don't recognize you or any of their friends—every moment in their lives would be like seeing the world for the first time.

    But don't be so quick to feel sorry for them. A recent study has found that fish have much better memories than we used to think. In fact, certain kinds of fish can even remember events from as long as 12 days ago, BBC reported.

In the study, researchers from MacEwan University in Canada trained a kind of fish called African cichlids to go to a certain area of their tank to get food. They then waited for 12 days before putting them back in the tank again.

    Researchers used computer software (软件)to monitor the fish's movements. They found that after such a long break the fish still went to the same place where they first got food. This suggested that they could remember their past experiences.

In fact, scientists had been thinking for a long time that African cichlids might have a good memory.

    An earlier study showed that they behaved aggressively (攻击性地) in front of certain fish, perhaps because they remembered their past fights. But until the latest findings, there was no clear evidence (证据).

    Just as a good memory can make our lives easier, it also plays an important part when a fish is trying to live in the wild.

"If fish are able to remember that a certain area has safe food, they will be able to go back to that area without putting their lives in danger," lead researcher Trevor Hamilton told Live Science.

For a long time, fish were placed far below chimpanzees (黑猩猩), dolphins and mice on the list of smart animals. But this study has given scientists a new understanding of their intelligence (智力).

    So next time you are watching your pet fish from outside the tank, perhaps you should feel closer to them——they may remember who you are.

When people travel to foreign countries, they often make some mistakes in understanding the local languages. When I  (live) in Europe, some Spanish (西班牙的）friends of mine decided to visit England. Before they left, they asked me for advicehow to find accommodation (住所). I suggested that theystay at "bed and breakfast" houses, so that they could have more chances(learn) about British culture. My friends accepted my advice, but they came back with some funny stories.

＂We didn't stay at 'bed and breakfast' houses, "they said, "because we foundmost families were away on holiday. ”

I thought this was strange.(final) I understood what had happened. My friends knew little English and thought "VACANCIES" meant vacation, becauseSpanish word for vacation is "vacaciones". So they didgo to the houses where the sign outside said "VACANCIES", which means there are free(room). Instead, they went to the houses where the sign said "NO VACANCIES". They thought this meant the peopleowned the houses were not away on holiday. But they found that these houses were all full. As a result,they stayed at hotels!

Artificial intelligence (AI) is technology that lets machines do things that need "thinking." It is a hard term to define(下定义) because AI isn't actually one thing. Rather it's a group of technologies that help machines get, understand and use information to perform tasks. The range of technologies is one of the reasons people use so many different terms to describe AI. In addition to artificial intelligence, terms like machine learning, cognitive computing and deep learning are common.

No matter which term is used, recent developments have received a lot of public attention. Some have welcomed the technology because of things that AI makes possible. For example, AI will have a big effect on areas like medicine and engineering. But the public attention has also produced a lot of fear and caution. In particular, many are concerned about the effects AI could have on people's jobs.

According to a recent study, nearly five percent of jobs will disappear because of AI. High on the list are jobs in the producing and mining industries, where systems powered by AI are already performing tasks that people used to do, such as assembling(组装) cars, digging tunnels and loading materials. In the future, self-driving cars and trucks that depend on AI will also steal jobs for drivers. Moreover, AI systems will do many tasks now performed by legal assistants and accountants.

On the other hand, AI will also create many new Jobs. More people will be needed to write software for AI systems as well as to set up and operate them. Meanwhile, jobs that require emotional intelligence, excellent communication skills and interaction with people will not be replaced by Al. These include jobs in fields like teaching, nursing, hairdressing and personal training.

    There are a lot of things that you should be careful with when you are alone at home. Read the following and learn how to protect yourself.

    Keep the door locked (锁着的) when you are alone at home. Many people think it is the best way to protect themselves.

    Keep a list of phone numbers to call for help, such as 110, the police station's or a neighbour's phone number.

    Be careful with the electrical appliances (电器). If you don't know how to use them, ask your parents for help.

    Look through the peep hole (猫眼) when you hear the doorbell. If there are strangers, ask "Who is that?" with the door locked and say "Come back later." Don't tell them that your parents are not at home. You should say "Mum is having a shower." or "Dad is sleeping." To ignore the doorbell is not a good idea because sometimes bad people ring doorbells to see if anyone's at home.

From far out in space, Earth looks like a blue ball. Since water covers three-fourths of the Earth's surface, blue is the color we see most. The continents (陆地）look brown, like small islands floating in the huge, blue sea. White clouds cover around the Earth like a light blanket（毯子）. The Earth is shaped like a sphere, or a ball. It is 25,000 miles around! It would take more than a year to walk around the whole planet. A spaceship can fly around the widest part of the sphere in only 90 minutes.

Even though spaceships have traveled to the Moon, people cannot visit the Moon without special suits. The Moon has no air or water. Plants and animals can't live there either. Astronauts first landed on the Moon in 1969. After that, there were six more trips to the Moon. They brought back Moon rocks, which scientists are still studying. There are holes, or craters(火山口), all over the Moon's surface. Scientists believe that meteorites（陨石）smashed into the Moon millions of years ago and formed the craters.

The Sun is the closest star to Earth. A star is a hot ball of burning gas. The Sun looks very big because it is so close. But the Sun is just a medium-sized star. Billions of far-away stars are much bigger than our Sun. The burning gases from the Sun are so hot that they warm the Earth from 93 million miles away! Even though the Sun is always shining, the night here on Earth is dark. That's because the Earth rotates, or turns around, every 24 hours. During the day, the Earth faces the Sun. Then we see light. During the night, the Earth turns away from the Sun. Then it faces the darkness of space.

Each day we learn more about the Earth, the Moon and the Sun.

    A sense of humor (幽默) can bring happiness to family life, since laughing together is a way to connect. And a good sense of humor also can make kids cleverer, healthier and better able to deal with difficulties, because a good sense of humor is not just about telling jokes, but about the response (反应) to things in a creative and funny way. It means you can see things from different sides and in different way.

Most of us may think humor is like our black hair or big feet. We have it since we are born. But a sense of humor is a completely learned quality (品质) that can be developed in kids, not something they're born with.

Kids, especially young kids may not understand what humor is, but you can do something funny to make them laugh. For example, you can put on a stupid hat and run after a 3-year-old boy, or pretend (假装) to carelessly fall into a river to make a first-grader laugh. As kids grow up, these things may be boring. But you can share some jokes as their sense of what's funny grows better.

Kids with a well-developed sense of humor are happier. They have the ability to find what's amusing in others. They can also deal with differences (their own and others') well. Kids who can enjoy and share humor are better liked by their friends and more able to go through hard times in childhood—from moving to a new town, to going to a new school. A good sense of humor is a skill that kids can use in their whole life to help them enjoy the funny parts of life, and not take themselves too seriously.

Water is important to all living things but some areas in the world are short of water a lot. So we should try to protect and save water.

A group of students from Zhejiang University have successfully developed an "air hand-washing

Machine". The machine uses an infrared ray induction system（红外线感应系统）, which can feel the presence of our hands. If it feels there are hands, the water with the air will come from the tap. And it has been proven that it is nearly as effective as traditional hand-washing. It uses only ten percent of the water that regular hand-washing does. The students have even set up a company to introduce the product to the public.

Li Qizhang, a member of the team that developed the machine, told a reporter that a model of their machine had already been placed in a classroom building at the university and it worked very well.

In 2014, a student called Chen Puyang first thought of the idea while he was washing his hands. Washing one's hands uses a lot of water, Chen thought. Would it be possible to replace the water with air? Others may not give the question a second thought. However, for Chen and Li, who were studying fluid mechanics（流体力学）at the time, this was considered to be an excellent idea.

Soon, Chen, Li and several classmates started on the project. After a year of research, the team came up with a gravity-driven（重力驱动）hand-washing machine successfully.

Do you ever find yourself standing in front of rubbish bins, not sure whether the piece of waste in your hand is recyclable or not? To solve this problem, four Hong Kong high school students have invented a smart rubbish bin that uses AI to sort(分类) the waste. The students named the bin Waste Collection Point.

Connected to a computer, the bin uses a camera to tell the kind of the waste it receives and sorts it into plastic, paper, glass, or other kinds. To make sure the bin can sort waste correctly, the team tested every product in the school shop and took at least500 pictures of each one. "To train the AI, we had to take many photos from different angles(角度), so it has a better rate of accuracy," said one of the students who built the AI system.

The idea of the smart bin was born two years ago, when the students were in Grade Ten. At that time, people from the city crowded into their village because of the COVID-19. They left behind a lot of rubbish and caused more pollution.

"All the bins were full, and there was even rubbish on the mountain," the students recalled, "Every weekend, we had to join the villagers in picking up the waste."

The students decided to develop a special recycling bin that would encourage people to protect the environment. Although school ended at 2 pm, the team would continue to work on their invention until 6 or 7 pm at school. Even when their school was closed last year, they would still meet and work together online.

"Our bin is now in its third generation(代). Before graduation, we hope it can be widely used in the city." The students said, "Then it will be easier than ever for people to recycle and protect our environment."