You might have seen beautiful rainbows in the sky before. They form when sunlight falls on water drops in the air. But in fact, moonlight can also create rainbows in the same way. They are called “moonbows”. They are similar to rainbows, but they are created by moonlight instead of direct sunlight.
Moonbows are rarer than rainbows. Different weather and astronomical （天文学的）conditions have to be just right for moonbows to be created.
The moon has to be very low in the sky-only 42 degrees from the horizon （地平线）. The moon period has to be a full moon or nearly full. The sky must be very dark for a moonbow to be watched clearly-any bright light can obscure it. Water drops must appear in the air in the opposite direction of the moon.
Moonbows appear on the opposite side of the moon and usually look white to the human eye. This is because their colors are not bright enough to be noticed by the human eye. It is possible, however, to view the colors in a moonbow using long exposure （长时间曝光）photography.
Moonbows more often appear in some locations around the world. Most of these locations usually have waterfalls, which create thin fog in the air. Some of these locations are the Yosemite National Park in California and Cumberland Falls State Resort Park in Kentucky, US; Victoria Falls on the border of Zambia and Zimbabwe; and Waimea in Hawaii, US.
Moonbows do really happen. So at a certain time and a certain place, when a moonbow happens to appear, you can’t miss it if you’re right there.
1. According to the first two paragraphs, moonbows are ________.| A．created by sunlight | B．much easier to find |
| C．seen during the day | D．more difficult to form |
| A．A half moon hangs high in the bright sky. |
| B．A full moon is 50 degrees from the horizon. |
| C．A nearly full moon hangs low in the dark sky. |
| D．Water drops are in the opposite direction of the sun. |
| A．cover | B．drop | C．connect | D．produce |
| A．Conditions of moonbows. | B．Background of moonbows. |
| C．Locations of moonbows. | D．Development of moonbows. |
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【推荐1】Have you ever seen the auroras (极光) in the sky? Cosmic radiation (宇宙辐射) creates these pretty lights in the North and South Pole areas. It seems that cosmic radiation is a beautiful gift from space. But for some people, it can be dangerous.
A 53-year-old fight attendant in South Korea, who spent about 1,022 hours flying each year, passed away due to cancer. A South Korean court connected his death to great exposure (暴露) to cosmic radiation. During his career, nearly half of his flights crossed the areas in and around the North Pole, where cosmic radiation is extremely strong.
① Cosmic radiation from space is hitting Earth nonstop, coming from both the sun and other stars in the Milky Way.
② Earth’s magnetic field (磁场) and atmosphere (大气层) protect us from most cosmic radiation. The magnetic field is strongest near the equator and weakest at the poles. People living at higher latitudes (纬度), like in Heilongjiang province, are exposed to a little bit more cosmic radiation than those living at lower latitudes, like in Hainan province. Also, when you go higher in an airplane, the thin atmosphere increases exposure to cosmic radiation.
③ For flight attendants crossing polar areas and for astronauts in space, cosmic radiation can create health risks. NASA reported that the radiation exposure faced by astronauts spending six months in space is the same as having 1,000 chest X-rays.
④ However, what makes cosmic radiation dangerous also makes it useful. The light speed and energy of cosmic radiation have provided wonderful ideas for treating tumors (肿瘤). Scientists can now produce man-made radiation similar to cosmic radiation. Compared to the present ways of treating tumors, it can kill tumors better with less damage to healthy parts of the body around them.
1. The death of the flight attendant is believed to have something to do with ________.| A．long flight hours | B．lower latitudes |
| C．strong cosmic radiation | D．a family history of cancer |
| A．① | B．② | C．③ | D．④ |
a. they are closer to the sun and stars b. they are at higher latitudes in space
c. space suit cannot prevent cosmic radiation d. there is not much atmosphere protecting them
| A．ac | B．bc | C．ad | D．cd |
| A．Cosmic radiation is very dangerous. | B．People can produce cosmic radiation. |
| C．Earth is filled with cosmic radiation. | D．Cosmic radiation helps fight cancer. |
【推荐2】Each astronaut has a special job to do as part of the team. Some astronauts learn how to put things together so they become good at fixing things. This is important because if something on a spaceship breaks the astronauts must be able to fix it themselves. Some astronauts are pilots who know how to fly airplanes. These astronauts have to study how to fly a spaceship. Other astronauts learn mostly about science. Their job is to learn how living things change when they are in space.
Although each astronaut has a special job, each of them has to learn how to work where there is no gravity(地球引力). When they are in a spaceship that is moving around the Earth, they can feel as if they didn't weigh anything. They are able to float(漂浮).
This sounds like fun, but it's not that fun. People are used to being on the Earth, but some people stay out in space for months. A lot of strange things happen to the body when it floats for that long.
Astronauts sometimes feel sick in space. It takes them a few days to get used to not weighing anything and being able to float.
Being in space also makes the astronauts’ legs weak. They call this “bird legs”. To help keep their legs strong, astronauts have to do exercise when they are in space.
1. What does the first paragraph mainly tell us?| A．What the science astronauts learn |
| B．How astronauts fly airplanes. |
| C．How to train to be an astronaut. |
| D．Different jobs astronauts do. |
| A．How to work where there is no gravity. |
| B．How to enjoy beautiful stars. |
| C．How to talk with their family. |
| D．How to plant some things. |
| A．To show some strange things happen to astronauts. |
| B．To show how astronauts stay healthy. |
| C．To tell us about some special astronauts |
| D．To tell us how to get used to floating. |
| A．Some famous astronauts. |
| B．Some exercise astronauts should do. |
| C．Something about astronauts. |
| D．How to study in space. |
Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. "This is long enough for other planets to have intelligent life，" say Shostak and Barnett. The second reason is size-the universe is huge. "Tools like the Hubble telescope(哈勃望远镜)have shown that there are at least 100 billion galaxies，" says Shostak. "And our galaxy，the Milk Way，has at least 100 billion stars. Some planets going around these stars might be similar to Earth."
In the past，it was hard to look for signs of intelligent life in the universe. But now，powerful telescopes(高倍望远镜)allow scientists to discover smaller planets-the size of Mars or Earth in other solar systems. These planets might have intelligent life.
Have beings from space already visited Earth? "Probably not，" says Shostak. "It's a long way away. However, intelligent beings may contact us in other ways，such as radio signs. In fact，they may be trying to communicate with us now，but we don't have the right tools to receive their messages. However, this is changing. By 2025，we could make contact with other life forms in our universe and we might help each other. "
1. What is the best title for Paragraph Two?
| A．The Age and Size of Earth |
| B．Our Galaxy: The Milk Way |
| C．Why Intelligent Life Might Exist |
| D．Earth: The Only Planet With Intelligent Life |
| A．There were not any smaller planets. |
| B．There were not any powerful telescopes. |
| C．The astronomers were not interested in them. |
| D．The Milk Way didn't exist at that time. |
| A．They are afraid of us. |
| B．It's a long way away. |
| C．They don't want to see us. |
| D．They don't know how to use radio signs. |
| A．Messages. | B．Tools. |
| C．Intelligent beings. | D．Radio signs. |
【推荐1】What is your dream life like in summer? It may be eating a watermelon in a house with an air conditioner（空调）. Watermelons came from Africa. Later, they came to the west of China along the Silk Road（丝绸之路）. Watermelons are Chinese people’s favorite. People from other countries want to know why Chinese people like watermelons more. Here are two reasons.
One is that watermelons have a good taste. And they have lots of vitamins（维生素）and minerals（矿物质）, which are good for people’s health. People would think of watermelons first when they buy fruits in summer. The other is that more than 90% of the world’s watermelons are from China each year. In supermarkets, we can know that watermelons are cheap in China. However, in Japan and Korea（韩国）, people are not so lucky. In Korea, a watermelon is about 20, 000’KRW (about 100 yuan). And in Japan people think eating a watermelon can be a show-off（炫耀）.
People are careful when they buy watermelons. Most of them usually knock at them and the sound can tell which one tastes the best. However, there are many ways to eat watermelons. For most people, it is cool to enjoy half a watermelon just with a spoon. There are also some ways we don’t often use. For example, in Xinjiang, people eat watermelons around the stove（炉子）and in Hainan, people eat watermelons even with salt. No matter how we eat watermelons, they make our summer better.
1. Watermelons may first come to _________ from Africa.| A．Shanghai | B．Beijing | C．Hainan | D．Xinjang |
| A．50 | B．200 | C．100 | D．400 |
| A．sizes | B．sounds | C．colors | D．minerals |
| A．With salt. | B．With vitamins. | C．Near the stove. | D．Near the Silk Road. |
| A．Chinese people love watermelons because they are tasty. |
| B．Watermelons are not expensive in Chinese supermarkets. |
| C．Most people enjoy half a watermelon with a spoon. |
| D．Most Japanese people can have watermelons. |
【推荐2】①Research has shown that dogs can help reduce bad feelings like stress and loneliness. Recently, scientists did an experiment which showed that dogs can also tell the difference between the smell of a person when they’re relaxed and when they’re stressed.
②Researchers worked with four dogs. They taught the dogs to use a special smell-testing device (装置) with three openings. The scientists trained the dogs to find the correct opening. Over time, the dogs were given harder and harder smelling jobs. The final goal was to see if they could smell stress in the breath and sweat (汗水) of a person.
③ All day long, our bodies go through changes and produce different chemicals. These chemicals come out in our breath and sweat, changing the way we smell. But it wasn’t known if stress could cause changes that couldn’t be discovered.
④So the researchers collected breath and sweat samples (样本) from 36 different people. They got samples when the people were calm, and also when they were stressed. Then the researchers collected two more sweat and breath samples. The scientists used one of the stressed smell.
⑤ Then came the challenge —the dogs have three choices: a sample from a calm person, a stressed sample from the same person, and a clean piece of cloth. The dogs did 720 tests. They correctly chose the stressed sample about 94% of the time.
⑥The results make it clear that dogs can tell the smell of stress. Scientists say the news could be especially useful in training service dogs, because their job is to help relieve the stress.
⑦ According to Clara Wilson, one of the researchers, the study shows that dogs don’t need to look at or listen to a person to detect stress — breath and sweat smells are enough. She added that the study could also help us understand more about the relationship between dogs and humans, and how much dogs know about how humans are feeling.
1. The scientists use samples of breath and sweat to test the dogs because _________.| A．they make our bodies smell different |
| B．our bodies become stronger every day |
| C．our bodies produce different sweat every day |
| D．stress could be changed by the sweat and breath |
| A．importance | B．influence | C．process | D．result |
| A．change | B．reduce | C．affect | D．discover |
| A．know when people are stressed |
| B．learn if dogs can smell stress |
| C．teach dogs to find the correct opening |
| D．check the breath and sweat of people |
【推荐3】It’s hard to turn down a tasty banana. They taste good and you don’t have to wash them before eating them. However, British scientists say that the fruit may disappear by 2050.
One reason for this is climate change. Scientists at the University of Exeter collected data(数据) from 27 countries that produce 86 percent of the world’s bananas. They found that climate change has improved growing conditions in 21 of these countries. In the past 60 years, the average yield(平均产量) has reached 1.37 tons of bananas per hectare(公顷).
However, if temperatures keep rising, this advantage will disappear. Ten of the countries, including India, the world’s biggest producer of bananas, will produce fewer bananas. By 2050, the fruit may die out.
Shouldn’t bananas grow more easily if it’s hotter outside? In fact, the perfect temperature range(范围) for growing bananas is between 24℃ and 32℃. If temperatures get too high, they will stop growing.
Diseases are another danger to bananas. Unlike other plants, the bananas we grow come from shoot cuttings(茎段) rather than seeds. This means that all banana plants have the same genotype(基因型). In other words, if a disease is able to kill one plant, it could kill them all.
One serious disease is called Panama. Caused by fungi(真菌) in the soil, it spreads easily. It has spread across South Asia, Africa, the Middle East and Australia. If one banana plantation(种植园) suffers from the disease, it will take 30 years until it is able to grow bananas again. Scientists haven’t found a cure for this disease yet.
根据短文内容,选择最佳答案。
1. What does the underlined word “this”in Paragraph 2 refer to(指)?
| A．A banana tastes great. |
| B．A banana will die out by 2050. |
| C．A banana is convenient to be eaten. |
| A．in the last 60 years, the average yield of bananas has increased |
| B．Panama has killed all the bananas in some areas like South Asia |
| C．the higher the temperature is, the better bananas will grow |
| A．The difficulties of growing bananas. |
| B．The perfect conditions of growing bananas. |
| C．The reasons for the disappearance of bananas. |
A． | B． | C． |
Dogs like living with people. They are very friendly. They can do many things for people. Some dogs help people to look after sheep, other dogs help them to find the lost children. And some of the dogs can help the blind (盲人). They are the Seeing Eve dogs. They work for the blind. Now we can see this kind of dogs all over the world.
The Seeing Eye dog is strong and easy to train (训练). He helps the blind to walk from place to place. Before a dog becomes a Seeing Eye dog, it must go to a training school for about three months.
First, the dog has to learn to sit or stay when he hears the trainer’s (训练师) call. In his next lesson, the dog learns to take his trainer across busy streets. The dog has many things to learn. At the end of the training school, he must take tests (测试). When it passes the test, it can become the Seeing Eye dog.
The new master may be a man, a woman, or even a child. It takes the dog and his blind master about a month to learn to work and live together.
1. The phrase Seeing Eve dogs has Chinese meaning ________.| A．猎犬 | B．警犬 | C．导盲犬 | D．搜救犬 |
| A．Finding their food. | B．Training other dogs. |
| C．Calling the police. | D．Walking from place to place. |
| A．Two days. | B．Few days. | C．A month. | D．Two months. |
【推荐2】There are about 6,000 languages that are spoken around the world. But 43 percent of these languages are dying out, according to UNESCO(联合国教科文组织). If no action is taken, some of these languages will become extinct.
Languages become endangered for many reasons. One is that some communities of native speakers of the endangered languages no longer exist, Huff post reported. These people sometimes leave their communities and move to cities or towns.
In addition, the languages of dominant (占主导地位的) cultures may drive other languages into extinction. To get better education and jobs, young people have to focus their attention on learning dominant languages rather than their own languages. Dominant languages include English, French and Mandarin.
Once a language dies, it rarely comes back to life. Governments across the globe are taking action to prevent this. In September, the US state of Alaska announced that the loss of indigenous (土著的) languages was an “emergency(紧急事件)”. It is now working to give new life to such languages, Quartz reported.
In New Zealand, the government has said it wants more than 20 percent of the country’s population to be able to speak basic Maori (毛利语), an indigenous language, by 2040. It plans to provide Maori lessons in all New Zealand schools by 2025, The New York Times reported.
China is also trying to protect its languages. About 130 languages are spoken in China, even more than the number of ethnic groups in the country. In 2015, the government started a project to record all the languages spoken in China, Xinhua reported. Universities like Minzu University of China have created minority language majors (专业) for their students.
1. What does the word “extinct” mean in Chinese?| A．不流行的 | B．灭绝的 | C．普通的 | D．持久的 |
| A．The learning of dominant languages. | B．The extinction of languages. |
| C．Action taken to save endangered languages. | D．The movement of speakers of endangered languages. |
| A．Languages are disappearing fast in New Zealand. |
| B．Maori lessons are already offered in all of the schools in New Zealand. |
| C．130 languages are endangered in China. |
| D．Making recordings is a way to protect languages. |
【推荐3】We all know plastic pollution has become a serious problem. One million plastic drinking bottles are thrown away every minute. What if we could use plastic waste to build roads? This is exactly what Toby Mc Cartney has done.
In 2019, McCartney’s UK-based company, MacRebur, built a plastic road in Elgin town, Scotland. The plastic waste was made into grains (颗粒) and then mixed with bitumen (沥青). The road looks just like any other road. But it has improved strength and is more stretchy (有弹性的) thanks to the plastic.
“Our technology can not only help solve the problem of plastic waste but also produce roads that deal better with changes in the weather,” McCartney said.
McCartney’s idea came from a trip to India. “I saw people in India would put plastic waste into potholes (路面的坑洼) and burn it. The plastic would melt down (融化) and fill the holes,” said McCartney.
“I knew that there must be some correspondences between plastic and bitumen, which both come from oil. That’s how I started to think about mixing them,” he said.
After lots of testing, McCartney found the perfect method. And now his company has built many plastic roads around the world. A one-kilometer stretch of road uses about 684,000 plastic bottles or 1.8 million plastic bags. The road itself can be recycled and the materials can be reused to build new roads.
“We’re just a small part of ending the plastic problems, but it’s nice to be part of it,” McCartney said. “I just don’t want my daughters to live in a world where there are more plastics in the ocean than fish.”
1. Compared with normal roads, the plastic road ________.a. is not easy to break b. is fit for hot weather c. is more stretchy d. costs more money
| A．ab | B．ac | C．bc | D．bd |
| A．too many changes in the weather |
| B．his wish to reduce plastic pollution |
| C．his knowledge of plastic and bitumen |
| D．Indian people’s way of dealing with potholes |
| A．competitions | B．connections | C．differences | D．reasons |
| A．children should also join to reduce plastic pollution |
| B．plastic pollution is becoming more and more serious |
| C．McCartney is ready to offer help in reducing plastic pollution |
| D．plastic problems will soon be solved with McCartney’s help |
| A．To describe how much a kid’s future matters. |
| B．To encourage every company to build a plastic road. |
| C．To help people understand how harmful plastic waste is. |
| D．To tell people plastic waste can be reused to build a road. |
