impossible; discover; different; get; close; call; might; although; larger; send |
Lots of scientists believe that there’s life on other planets. Because of this, they keep doing research about the universe. They have sent astronauts to the moon. And they have
2 . For thousands of years, humans have explored (探索) the Earth. Nowadays, we are exploring space. Astronomers are the modern-day explorers. Now, many astronomers are looking for new planets and new places for humans to live in the future. But where do astronomers start exploring?
First of all, astronomers look for a star. That’s because our own Earth moves around a star—the Sun. More importantly, it is neither too far from nor too near to the Sun for heat and light. So when astronomers have found the star, they look at the planets around it. In recent years, astronomers have found nearly 400 new planets with stars. However, many of these planets are either too near to the star or too far away.
However, if the planet is in a good place, astronomers look for three key things: water, air and rock (岩石). Water is the most important because all life needs water. Humans can drink it and they can also grow plants with water. And plants produce air for humans to breathe and food to eat. Rock on a planet is also important. That’s because there is often water under the rock.
After many years of exploring, astronomers have found a planet like the Earth. It’s Gliese 581g and it’s near a star. The astronomers think it has water and rock and the temperature is between -31℃ and -12℃. That’s cold, but not colder than Antarctica or the Arctic Circle, for example, Gliese 581g is bigger than the Earth. A year on Gliese 581g is only 37 Earth days, not 365 Earth days. But astronomers do not think these are big differences and some of them think Gliese 581g will be a new Earth. However, Gliese 581g is twenty light years from the Earth.
1. How do astronomers discover a new planet for humans to live on? Choose the right order.a. Astronomers look for three key things.
b. Astronomers look for and find a right star.
c. Astronomers look at the planets around the star.
| A．a-b-c. | B．b-a-c. | C．b-c-a. | D．c-a-b. |
| A．Water. | B．Air. | C．Rock. | D．Food. |
| A．the Earth | B．Gliese 581g | C．the Sun | D．Gliese |
| A．37 | B．365 | C．10 | D．15 |
| A．Gliese 581g is already a new Earth. |
| B．There are some planets like our Earth. |
| C．Water, air and rock are important. |
| D．Astronomers are looking for a new Earth. |
fly; we; city; send; near; plant; shine; planet; look; hundred |
From a plane you can see the fields,
The moon is our
The moon hasn’t its own light. It
In fact the moon isn’t as near as it looks. It is three
4 . In the universe, as we know, there is the sun, the moon, the earth and many stars. Through our geography lessons, we know the earth goes around the sun, and the moon goes around the earth. We have day and night because the earth keeps turning all the time. When our part of the earth turns to the sun, it is day. When our part of the earth turns away from the sun, it is night.
Just because the moon is closer to the earth than the sun, it looks much bigger than the sun. Big things look smaller when they are farther, and small things also look bigger when they are nearer.
The sun is bright enough to give out very strong light. The moon can’t give out any light at all, but it looks quite bright too. Why? In fact, the light from the moon comes from the sun. The moon looks much bigger and brighter than the stars. But actually the stars are much bigger and brighter than the moon. They look smaller than the moon also because they are farther away from the earth.
There are still many other planets in the solar system (太阳系). All of them move round the sun. But of all these planets, only on the earth there are living things and people can only live on the earth too. At 9:00 am on October 15th, 2003, Chinese pilot Yang Liwei was sent up to space. He stayed there for 21 hours. It was the first time for Chinese to get into space.
1. When our part of the earth turns away from the sun, the other part of the earth is ______.| A．night | B．day | C．evening |
| A．the earth | B．the moon | C．the sun |
| A．On November 15th, 2003. | B．On October 16th, 2003. | C．On October 15th, 2003. |
| A．The moon goes around the earth, and it can’t give out any light at all. |
| B．The moon goes around the sun, and its light is from the sun. |
| C．The sun goes around the earth, and it can give out very strong light. |
1. How is the show about space?
| A．Boring. | B．Exciting | C．Interesting. |
| A．The water on Mars. | B．The photos of the moon. | C．The life in space. |
| call, impossible, send, reach, different, get, close, might, although, large, about, must |
Lots of scientists believe there’s life on other planets. Because of this, they keep doing research
Scientists have always wanted to know more about the universe.
Years ago, they knew many things about the moon. They knew how big it was and how far away it was from the Earth. But they wanted to know more about it. They thought the best way was to send men to the moon.
The moon is about 384,000 kilometers away from the Earth. A plane can not fly to the moon, because the air reaches only 240 kilometers away from the Earth. But something can fly even when there is no air. That is the rocket.
How does a rocket fly? There is gas (气体) in the rocket. When the gas is made very hot inside the rocket, it will rush out of the end of the rocket, so it can make the rocket fly up into the sky.
Rockets can fly out into the space. Rockets with men in them have been to the moon. Several satellites without men in them have flown to another planet much farther away than the moon. One day rockets may be able to go to any place in space.
1. Scientists have known ________ the moon was.| A．how long | B．how heavy | C．how big |
| A．there is no air above 240 kilometers away from the Earth |
| B．there is no gas in the plane |
| C．the plane is not strong enough |
| A．keeping the air in the rocket fresh |
| B．making the rocket fly up |
| C．keeping the men in the rocket warm |
| A．the stars | B．the satellites of the Sun | C．another planet much farther away than the moon |
8 . What do black holes look like? Human beings have wanted to know about it for a long time. In 2019, we finally got the answer. They look like dark circles with a bright ring around the outside.
Scientists took the world’s first photo of a black hole. Scientists didn’t use a camera to take the picture. They used eight radio telescopes in different places around the world. Telescopes got signals (信号) from the black hole. Scientists used computers to process (处理) the signals. It took them two years to get the final picture.
The black hole is very far from Earth—about 55 million light years away. One light year is the journey that light travels in one year. One light year is about 9 trillion (万亿) kilometers.
This isn’t the only black hole in the universe. In fact, scientists believe every large galaxy (星系) has a big black hole at its center. The one in our galaxy is called Sagittarius A.
Black holes are some of the most mysterious (神秘的) things in the universe. This photo can help us learn more about them.
1. What do we know about black holes?| A．They are dark holes with a bright center. |
| B．They are many black circles inside each other. |
| C．They are black holes with colorful rings in the center. |
| D．They are dark circles with a bright ring around the outside. |
| A．Scientists took the picture of the black hole with a camera. |
| B．The black holes aren’t very far from the Earth. |
| C．The picture of the black hole can help us learn a lot about them. |
| D．Sagittarius A is the only black hole in the universe. |
| A．In a science magazine. | B．In a storybook. |
| C．In a travel guidebook. | D．In a physics exercise. |
1. How does Betty know the news?
| A．On the radio. | B．In the newspaper. | C．On the Internet. |
| A．The life on the moon. | B．The spaceship to Mars. | C．The sun and other stars. |
Humans have always been interested in the moon. About 2, 000 years ago, scientists had already known that the moon moves around the earth and where it would be in the sky at different times of the year. In old times, everything about the moon was learned by watching it carefully at night.
When scientists could use telescopes (望远镜) to study the moon more closely, they found the moon was made of rocks. Most scientists thought moon rocks would be different from those on earth. This was because they believed the moon had once been a planet that was caught in the earth’s gravity millions of years ago.
In 1969, moon rocks were finally brought to the earth and studied. Much to their surprise, scientists found that, except for water, the moon and the earth were made of the same things. Once again, new ideas were needed for this new study.
After years of study, most scientists now think that the moon was once part of the earth. They believe very early in its history, maybe 4 million years ago, something that was about the size of Mars hit the earth. This sent billions of rocks into space around our planet. These rocks slowly joined together and after many years became the moon.
Humans’ steps of exploring the moon will never stop. In the future, even though our ideas about the moon may change again, we’ll still show an interest in it.
1. At first, most scientists thought moon rocks were2.
3. Now most scientists think the moon once belonged to
4. People will never stop
5. How did people learn about the moon in ancient times?
