A study says the origin of human is in Botswana. Researchers said they used DNA to find out where modern humans came from. They believe all our roots (根) are in an area of northern Botswana. Humans were there 200,000 years ago. They lived there for at least 70,000 years and then migrated (迁徙) around the African continent. They then started moving to Europe and Asia. Researcher Professor Vanessa Hays, from the University of Sydney, said, “We’ve known for a long time that modern humans originated in Africa about 200,000 years ago.”
The researchers made sure of an area called Okavango as where we came from. There used to be a big lake but it is now a salt flat (盐碱地). People had water, hunting and farmland. Scientists studied DNA from 200 people who live near the area today. They are from the Khoisan people, who live in modern-day South Africa and Namibia. They had a lot of DNA called L0. Professor Hayes explained why L0 is important. She said, “Whenever a Dew migration (迁徙) happens, our L0 records that migration event as a time-stamp. Everyone walking around today comes from this region.”
1. Where did modern humans first come from according to the passage?A.Botswana. | B.Europe. | C.Asia. | D.India. |
A.About 70,000 years ago. | B.About 90,000 years ago. |
C.About 20,000 years ago. | D.About 200,000 years ago. |
A.200 people who live near Okavango had a lot of L0 | B.People with L0 had water, hunting and farmland |
C.People with L0 are from the Khoisan people | D.L0 records people’s migration as a time-stamp |
A.A tour guide in Africa. | B.An English teacher in junior high school. |
C.A scientist of human origin. | D.A student who studies math in university. |
相似题推荐
If you look carefully at the plants around you, you will find that there are two kinds of plants: flowering plants and non-flowering(不开花的) plants.
Flowering plants can make seeds(种子). The seeds are protected by the fruits. Some fruits have one seed, some have two, three or four, and some have many seeds. But a few fruits have no seeds at all. An example of a fruit without seeds is the banana fruit.
Most non-flowering plants do not grow from seeds. They grow from spores(孢子). Spores are very, very small. Some spores are so small and light that they can float in the air. We may say that spores are quite the same as seeds. When these spores fall on wet and shady(阴凉的) places, they usually grow into new plants.
1. What fact does the passage lead you to believe?
A.Of all living things, animals are most important. |
B.Spores are seeds. |
C.All fruits of flowering plants have seeds. |
D.Without plants, man will die out. |
A.how plants can make food from air |
B.how spores grow into new plants |
C.why some plants have no seeds |
D.why non-flowering plants are more important than flowering plants |
A.a story book | B.a novel |
C.a science magazine | D.a laboratory report |
【推荐2】It’s said that cats are not just pets to us all these years. They are, in fact, learning from their owners and taking them as models. Scary, huh?
A new study from the University of Messina shows that indoor cats who live closely to their owners copy the lives of their owners. For example, they sleep at the same time and eat at the same time. Just like a parent for a child, the same is true for a cat owner and his cat.
Many owners think their cats are as family members, so they spend much time with cats, hoping to give the best care and love for their cats. This is one of reasons the cats learn from their owner’s actions.
Another reason is that cats are clever animals with a long memory. Jane Brunt, director of the Catalyst Council, told Discovery News. “Cats watch us and notice our actions, knowing where their food is and what time to eat meals, where the washing areas are and how to open the cupboard door that’s closed.”
A new study also shows that cats understand 25—35 basic men’s words, such as food, eat, sit, no, stay, and stand. If owners train a cat to learn these words, cats will got closer to them. But in fact, cats can’t understand our ‘meows’.
So try to do better when you are in front of cats. If you spend a lot of time searching the kitchen, your cat will copy you and take food to its bowl for the night meal, too. That’s why cat owners and cats overweight rates often seem to synchronize.
Next time you reach for your kitchen, think twice. If your cat is watching, maybe she will overeat as well.
1. The text is mainly about ________.A.cats and owners |
B.cats and home |
C.cats and language |
D.cats and parents |
A.change quickly | B.go down |
C.get lower | D.be the same |
A.Cats can learn from men’s actions. |
B.Cat can’t find food from closed cupboard. |
C.Cats are always looking at their owners. |
D.Cats understand most of our language. |
A.people need to live with the cats |
B.children can keep cats in their houses |
C.people should share the story of cats and men |
D.pet owners should have healthier ways of life |
![](https://img.xkw.com/dksih/QBM/2022/3/30/2947551187640320/2952926179360768/STEM/2987caf884e74c8a8d6f25778ab6ff2c.png?resizew=103)
①The 2022 Beijing Winter Olympic Games opened on February 4, which coincided with “Lichun,” the first of the 24 solar terms(节气)in the traditional Chinese lunar calendar, showing the start of spring. “Lichun” also became an important element at the opening ceremony.
②Lichun is called “Start of Spring” in English. It is the first solar term in the year. It also shows the change of the season and marks the end of winter and the beginning of spring. The date for Lichun usually comes on February 4 or February 5 in solar calendar. After Lichun, days become longer and nights become shorter, while weather is getting warmer. The following is some information about this solar term.
Stand the egg
③In China, it is said that the egg can be set up on the first day of the spring. It is believed that if someone can make the egg stand on the first day of spring, he will have good luck in the future. Try to stand eggs today on your own. If you succeed in the challenge, it means good luck is coming.
Hold a special ceremony(仪式)
④People in China began holding a special ceremony on the day of Start of Spring about 3,000 years ago. In ancient China, people mainly lived on farming, and the change of seasons greatly influenced farming. Spring is the season for planting. After Lichun farmers may start to work in the field. And vitality(活力)heads back to all lives. For city people, time has come for them to do outdoor activities and enjoy warm sunshine.
Eat special food—Chunjuan
⑤People try to eat something new to keep the spring. There has been a long history of eating chunjuan during Lichun. People will wrap some vegetables with chunjuan. Besides enjoying chunjuan with vegetables, farmers will also send chunjuan as presents to each other.
1. Which of the following Chinese poem is about Lichun?A.泥牛鞭散六街尘,生菜挑来叶叶春 | B.桂轮开子夜,萤火照空时 |
C.闻道新年入山里,蛰虫惊动春风起 | D.露从今夜白,月是故乡明 |
A.to be healthy | B.to have good luck | C.just for fun | D.to succeed |
A.Warm sunshine. | B.The change of seasons. | C.The planting skills. | D.The outdoor activities. |
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A.![]() | B.![]() | C.![]() | D.![]() |
【推荐1】Hyperloop: the train of the future?
We’re going through the Nevada desert, north of Las Vegas, for having a look at what its supporters believe is the future of transport. This is Hyperloop - an attempt to send passengers rushing at 700 miles an hour through a vacuum tube.
Many think that’s impossible, but this project came back last year of virgin America Inc. with Sir Richard Branson becoming chair-man. In this 500-metre test track, they say they have shown that the technology works, though they’ve not yet put any human beings on board. The head of engineering, a space scientist from NASA, sees no reason why people might be frightened.
Anita Sengupta, Head of Engineering, Virgin Hyperloop One
“The Hyperloop is a maglev train in a vacuum system. And so you can also think of it as an aircraft flying at 200,000 feet high so people don’t have any problem flying in aeroplanes and people don’t have any problem going in maglev trains. This is simply joining the two and allows you to be more energy - saving.” The Virgin Hyperloop team have said they could take passengers from London to Edinburgh in 50 minutes or cut the journey between. New York and Boston to under half an hour.
Did you know?
The word ‘maglev’ is a combination (结合)of the words ‘magnetic’ and ‘levitation’. This is because the system uses magnets to levitate(使浮起)the train. This reduces friction(摩擦力)-- the force that makes it difficult for things to move freely when they are touching each other -- and increases speed. The first maglev train operated in Hamburg, Germany in 1979.
1. You are likely to see Hyperloop in ________.A.City of Las Vegas | B.Nevada Desert | C.NASA Base | D.Hamburg, Germany |
A.human beings were put on board | B.the vacuum tube was completed last year |
C.Sir Richard Branson became chairman | D.scientists solved two problems of transport |
A.effect | B.effort | C.event | D.example |
A.rise to 200,000 feet high | B.rush in a vacuum tube |
C.float because of the magnets | D.reduce friction of the air |
A.Head of the Virgin Hyperloop Team is a space scientist. |
B.The first maglev train was invented in the Untied States. |
C.Most people have confidence in the Hyperloop project. |
D.Hyperloop has sent passengers from New York to Boston. |
A.a vacuum tube testing a maglev train system |
B.an aeroplane flying at 700miles an hour |
C.a maglev train floating on the railway tracks |
D.a maglev tain traveling in a vacuum tube |
【推荐2】An international team of scientists says it has discovered two new “super-Earth” type planets about 100 light-years away, one of which may be suitable for life.
Unlike any of the planets in our solar system, the nearly 1,600 known super-Earths are larger than Earth, but lighter than icy planets like Uranus and Neptune.
Researchers at Belgium’s University of Liège said that they found another one while using Earth-based telescopes to check the existence(存在) of a different planet first discovered by a NASA satellite in the same solar system.
NASA’s satellite found planet LP 890-9b, which is about 30% larger than Earth and orbits its sun in just 2.7 days. ULiège researchers used their telescopes in Spain to take a closer look at the planet. That’s when the stargazers(天文学家) discovered another planet, LP 890-9c, which is 40% larger than Earth and takes 8.5 days to orbit its sun.
Francisco Pozuelos, a researcher, said that the planet could be suitable to life though being a 3.7 million miles from its sun. Earth, by comparison, is located over 93 million miles away from our sun. “Although this planet orbits very close to its star, at a distance about 10 times shorter than that of Mercury around our Sun, the amount of stellar irradiation(照射) it receives is still low, and could allow the presence of liquid water on the planet’s surface, if it has enough air,” Pozuelos said. “This is because the star LP 890-9 is about 6.5 times smaller than the Sun and has a surface temperature half that of our star.”
1. How did ULiège researchers discover LP 890-9c?A.They discovered it by accident. | B.They discovered it with NASA’s help. |
C.They discovered it with Pozuelos’ advice. | D.They discovered it with telescopes in Belguim. |
A.They are all suitable for life. | B.They are much bigger than Earth. |
C.They are heavier than Neptune. | D.They are 100 light-years away from Earth. |
A.How the planet was discovered. | B.Why the planet may be the suitable to life. |
C.Pozuelos’ role in the discovery of the planet. | D.Comparison’s role between LP 890-9 and earth. |
![](https://img.xkw.com/dksih/QBM/2022/5/4/2972391375937536/2972442720436224/STEM/fe209ebe08ca4af198e50af97d59cff9.png?resizew=184)
It is a common experience: You’re checking through a social media page, and you see pictures of friends traveling or going to parties. Suddenly you start to wonder why you are not doing those things. Are you missing out on something fun or exciting? This experience is known as FOMO—the fear of missing out. In some ways, people have always been worried about missing out on social events. But with the rise of social media, FOMO is becoming much more common.
While wanting to take part in exciting things is completely normal, it can bring about some negative (负面的) effects. For some people, it leads to an obsession (沉迷) with checking their phones to find out what other people are doing. Even while doing things that are fun or necessary, people can feel like there’s something better going on elsewhere. This strong wish to connect can make them disconnect from the people they are actually with. It stops them from being satisfied with the good things in their lives. It can even be dangerous; some people try to check messages while driving.
So what can we do to overcome FOMO? Firstly, it is important to remember that what people prefer to pick and choose to post on social media doesn’t necessarily show their life overall, so we only know a small part of anyone else’s life. It is also important to accept your limitations. You can’t be everywhere and do everything that might be interesting, and that’s OK. It might even be necessary to turn off your phone or log out of social media for a while. Stay away from the constant reminders of everything that’s happening in the world. You can even set particular times in your day to check email or social media. By stepping away for a time, you can view others’ lives in a reasonable way. Finally, focus on the things in front of you. Relish them, do them well and let everything else go. When you are fully involved in life, you will worry less about what you are not doing.
Don’t let the fear of missing out cause you to miss out on the good things you have in life. Relax, enjoy what you do and let other people enjoy their lives without envying (羡慕,嫉妒) them.
1. Experiencing FOMO, people may ________.A.like to drive fast | B.miss out on social events |
C.prefer to stay alone | D.be unsatisfied with real life |
A.Break. | B.Change. | C.Enjoy. | D.Remember. |
A.Breaking their own limitations. |
B.Staying away from social media. |
C.Making friends as many as possible. |
D.Checking social media at particular times. |