How many things can you see in the night sky? A lot! On a clear night you can see the moon, some planets, and thousands of sparking（闪烁的）stars.
You can see even more with a telescope. You might see that many stars look larger than others. You might see that some stars that look white are really red or blue. With bigger and bigger telescopes you can see more and more objects in the sky. And you can see those objects in more and more detail.
But scientists believe there are some things in the sky that we will never see. We won’t see them with the biggest telescope（望远镜）in the world on the clearest night of the year. That’s because they’re invisible. They’re the mysterious dead stars called black holes.
You might find it hard to imagine that stars die. After all, our sun is a star. Year after year we see it up in the sky, burning brightly and giving us heat and light. The Sun certainly doesn’t seem to be getting old or weak. But stars do burn out and die after billions of years.
As a star’s gases（气体）burn, they give off light and heat. But when the gases run out, the star stops burning and begins to die.
So next time you look up at the night sky, remember: there’s more in the sky than we can see!
根据短文内容选择最佳答案
1. The underlined word “invisible” in the passage means“________”in Chinese.
| A．听不见的 | B．看不见的 | C．摸不着的 |
| A．a planet | B．a sky | C．a star |
| A．give off heat | B．get weak | C．run out |
| A．The sun certainly seems to be getting old and weak. |
| B．We might see that some stars that look white are really red and blue with a telescope. |
| C．We might see that many stars look larger than others with a telescope |
| A．How stars burn out | B．What dead stars are | C．How we can see more stars |
相似题推荐
【推荐1】Have you ever dreamed of traveling in space? To travel in space, we first have to work out where our food will come from.
Today's space travellers don't go to the Moon or Mars. They go to the International Space Station（ISS）. There, the spacemen live for weeks to months.
If you visited the ISS years ago, nearly every kind of food you ate would have come from the Earth.
In 2014, scientists sent the ISS a space garden with some vegetable seeds（种子）. With water and some light, the vegetables in the garden grew. Those were the first foods being grown on the ISS. But the spacemen couldn't eat them and had to send them back to the Earth. The next year, after scientists made sure they were safe, the spacemen grew a second crop. This time the vegetables were ready for the spacemen to eat.
Gardening is different in space than it is on Earth. Without gravity, plants don't know which way is up. But they learn how to grow. They send their leaves in the direction of light and their roots into the soil.
The spacemen also have grown vegetables as well as flowers. It's important to know a plant can flower in space, because flowering is part of how some plants make fruit.
While the space garden is small for now, hopefully it could one day help provide people with food on long-time space trips.
1. Years ago, where did most of the food on the ISS come from?| A．The Mars. | B．The Earth. | C．The Moon. | D．The space garden. |
| A．The vegetables didn't taste good. |
| B．The spacemen didn't like vegetables. |
| C．The vegetables might not be safe to eat. |
| D．The scientists wanted to eat the vegetables first. |
| A．The spacemen. | B．The scientists. |
| C．The vegetables. | D．The water and light. |
| A．They stop growing. | B．They never grow up. |
| C．They grow in the direction of light. | D．They grow in the direction of the Earth. |
| A．a dream to travel in space. | B．plants in the space garden. |
| C．a trip to the Moon and Mars. | D．vegetable seeds from the Earth. |
【推荐2】The sun comes out in the morning and sets at night, and then the moon rises. Right? Then how come we can see the moon during the day sometimes?
The moon and the sun don’t actually take turns in the sky. The earth goes around the sun, and the moon goes around the earth. All three are spinning (旋转) in space all the time.
The moon moves through the sky night and day. Much of the time, the sunlight is so bright that we can’t see the moon during the day.
The sun is a very hot fire ball, which gives off both heat and light. But the moon is made of rock, it has no fire, and it is not hot or bright at all. What we call moonlight is actually sunlight bouncing off the moon, the same way that sunlight bounces off the glass in the window. They look like they’re lighting up, but they’re really just passing the sunlight along.
How bright the moon is depends on where it is in the sky. If the moon is between the earth and the sun, it doesn’t bounce any sunlight to us at all, and it is very hard to see, even at night. This is called a new moon.
When the moon is behind the earth, it shines very brightly. We call this a full moon. Sometimes, when the moon is very bright, we can see it even during the daytime.
1. Much of the time, we can’t see the moon during the day because ______.| A．the sunlight is so bright | B．the moon goes around the earth |
| C．the sun gives off heat and light | D．the moon is self-turning in space |
| A．闪光 | B．反射 | C．移动 | D．照耀 |
| A．in front of the earth | B．behind the sun |
| C．between the earth and the sun | D．behind the earth |
| A．the moon has its own light |
| B．there is no heat on the moon |
| C．the moonlight we see is the sunlight |
| D．the moon and the sun don’t appear at the same time |
| A．How Does the Moon Pass the Sunlight Along? |
| B．When Can We See a New Moon or a Full Moon? |
| C．Why Can We Sometimes See the Moon During the Day? |
| D．Why Don't the Moon and the Sun Take Turns in the Sky? |
【推荐3】NASA’s space scientists were closely watching a very large asteroid (小行星) that flew past Earth recently.
Asteroid 2015 DR215 was on NASA’s “close approach(接近)” list. But don’t worry, it was a safe distance (距离) away! It was thought to have passed Earth at a distance of 4.1 million miles away. So it was not a dangerous asteroid for us! The asteroid is around 1,600 feet wide, which is three times larger than the Great Pyramid in Egypt. What are asteroids? Asteroids are large space rocks in our solar system (太阳系). Sometimes they are called NEOs-Near Earth Objects. Until today, about 26,000 asteroids have passed Earth, according to NASA.
There are lots of asteroids that NASA watches all the time. They are usually 140 meters or above and can be a threat (威胁). The last big asteroid to actually hit Earth was 66 million years ago. This one caused the dinosaurs to die out. In fact, many smaller asteroids fly to Earth the whole time. But because of their much smaller size, they get burnt up in the atmosphere (大气层) before they hit Earth. Therefore, they can’t bring serious results.
1. What were the NASA’s scientists closely watching recently?| A．A strange plane. | B．A small spaceship. | C．A very small asteroid. | D．A very large asteroid. |
| A．The asteroid is around 1,500 feet wide. | B．The asteroid is around 1,000 feet wide. |
| C．The asteroid is around 1,600 feet wide. | D．The asteroid is around 1,400 feet wide. |
| A．200. | B．2,600. | C．26,000. | D．260. |
| A．The earth died out. | B．The dinosaurs to die out. |
| C．The animals died out. | D．The living things died out. |
| A．their size is so small |
| B．they get burnt up in the atmosphere(大气层) before they hit Earth |
| C．both A and B |
| D．they are afraid of the earth |
【推荐1】A cold is a common illness(疾病). It often starts with a sore throat. And you usually have a headache, too. It’s not serious, but you can feel very bad.
What should you do when you have a cold? You should have a good rest first. It’s good to drink a lot of water, too. You can see a doctor and take some medicine. Maybe you can also try some Chinese medicine that is now very popular around the world.
What should you do to keep from catching a cold? One important way is to exercise more often. Running, swimming or even walking can help a lot. Try to exercise for at least 30 minutes a day. It’s also important to go to bed and get up early. Studies show that the cold or flu virus(流感病毒) can live on our hands for a long time. So you should wash your hands with soap. Finally, it’ s important to have a balanced diet(均衡饮食).
If you can do these, you will hardly ever catch a cold again.
根据短文内容，选择最佳答案。
1. What is a cold like?
| A．It’s scary. | B．It’s good. |
| C．It’s very serious. | D．It brings some problems. |
| A．Go to a doctor. | B．Sleep early and get up late. |
| C．Exercise more often. | D．Drink much cold water. |
| A．Three. | B．Four. | C．Five. | D．Six. |
| A．Because it makes our hands smell good. |
| B．Because it makes our hands nicer. |
| C．Because it may help keep the flu virus away. |
| D．Because it is not expensive for us to buy soap. |
| A．Only Chinese medicine can help stop a cold. |
| B．We should run or swim when we have a cold. |
| C．The most important way to stop a cold is to drink lots of water. |
| D．Good eating habits and much exercise can help us stay away from a cold. |
【推荐2】Experts say that students usually need eight to ten hours’ sleep at night, but most Chinese students do not get enough sleep. Some Chinese parents are usually glad to see their children studying late. They will think their children work very hard, but not all parents are happy about this. Once a mother told us that every morning her 10-year-old boy put up one finger with his eyes still closed, begging（请求）for one more minute to sleep. Like thousands of students “early birds” in China, he has to get up before six every morning.
A report shows that without a good night sleep, students seem to be weaker（虚弱）than they should be. Many students have fallen asleep during class at one time or another. Too much homework is not the only reason why students stay up late. Some watch TV or play the computer games late into the night.
Experts have ever said that the students should develop good study habits. So some clever students never study late, and they are able to work well in class.
1. Which is the good sleep habit according to experts?| A．Lily usually sleeps six hours at night. |
| B．Tom usually sleeps nine hours at night. |
| C．Tina usually plays the computer games late into the night. |
| A．People who eat breakfast early. |
| B．People who want to fly like a bird. |
| C．People who get up early every morning. |
| A．All Chinese parents are glad to see their children studying late. |
| B．Most clever students won’t work well in class without studying late. |
| C．Without a good night sleep, students will be weaker than they should be. |
| A．Students should develop good sleep habits. |
| B．Chinese parents worry about their children. |
| C．Too much homework is the reason why students stay up late. |
【推荐3】Dragons are not real animals, but look like a combination (组合体) of many animals such as snakes, fish and deer. They have two horns (角) and a long moustache (胡子). With fantastic powers, they fly in the sky or swim in the sea. They can make rain, too. The Chinese dragon is a symbol of strength and goodluck. The emperors of ancient China loved dragons. Their clothes were covered with pictures of dragons.
We are proud to call ourselves the “descendants (传人) of the dragon”. In Chinese, “excellent” people are often called “dragons”. A number of Chinese sayings and idioms talk about dragons, for example, “Hoping one's child will become a dragon,” which means hoping he or she will be successful.
It is said that people born in the Year of the Dragon have certain characteristics. They are creative, confident, brave and quick-tempered. There are some famous “dragons” who have done excellent things, for example, Deng Xiaoping, the famous businessman Li Jiacheng and the movie star Zhao Wei. They are all very successful.
There are also some traditional festivals about dragons in China, such as Dragon Head – Raising Day and Dragon Boat Festival. We have different kinds of activities to celebrate them. These two festivals come every year, but the Year of the Dragon comes every twelve years. It was the year of the Dragon five years ago.
The dragon is very important in Chinese culture. As the “descendants of the dragon”, it is necessary for us to know the views on dragons in our culture. It can help us understand why our parents always want us to be “dragons”.
根据短文内容，选择正确答案。
1. What does the Chinese dragon symbolize?
| A．A combination of many animals. | B．Chinese sayings and idioms. |
| C．Traditional festivals. | D．Strength and good luck. |
| A．龙马精神 | B．龙飞凤舞 | C．望子成龙 | D．龙腾虎跃 |
| A．creative, confident, brave and powerful |
| B．creative, confident, brave and quick-tempered |
| C．lovely, confident, brave and quick-tempered |
| D．lucky, confident, creative and successful |
| A．1997. | B．1998. | C．2012. | D．2018. |
| A．Dragons are real animals. |
| B．There are many Chinese sayings and idioms about dragons. |
| C．People born in the Year of the Dragon must be successful. |
| D．The “descendants of the dragon” are often called “dragons”. |
