If you want to make more friends, sharing is_________.
A.serious B.outgoing C.talented D.necessary
—Don't worry. I believe you have the __________to solve the problem.
—Thank you. I'll try it again.
A.ability B.secret C.background D.course
We cannot change yesterday, __________we can build today for tomorrow.
A.and B.but C.or D.so
— Have you ever been to Switzerland?
—You mean _________capital of clocks and watches? Yes. It's a beautiful country.
A.a B.an C.the D./
For thousands of years, humans have explored(探索) the Earth. Nowadays, we are exploring space. Astronomers (天文学家) are modern-day explorers. Now, many astronomers are looking for new planets and new places of humans to live in the future. But where do astronomers start looking?
First of all, astronomers look for a star. That’s because our own Earth moves around a star (the Sun). More importantly, it is the correct distance(距离) from 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 position, astronomers look for three key things: water, air and rock. Water is 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 scrutinizing, astronomers have found a planet that is similar to the Earth. It’s Gliese 581g and it’s near a star. The astronomers think it has water and rock and the average(平均的) temperature is between-310C and -120C. That’s cold，but not colder than Antarctica or Arctic Circle, for example, Gliese 581g is bigger than the Earth. A year on Gliese 581g is only 37 Earth days instead of 365. But astronomers do not think there are big differences and some them thing Gliese 581g will be a new Earth. However, Gliese 581g is twenty light years from the Earth.
1.What do astronomers have to find first before starting to look for a new place for humans to have?
A. A new star. B. A new planet. C. Some heat. D. Some light.
2.What does the rock on a planet tell us?
A. The star is a right position.
B. We may discover water under it.
C. The planet is too near to the Sun.
D. There can be air around the rock.
3.What does the underlined word “scrutinizing” mean in the last paragraph?
A. discussing B. waiting C. looking D. traveling
4.What’s the main idea of the text?
A. Gliese 581g is already a new Earth.
B. There are planets similar to our Earth.
C. Water, air and rock are important.
D. Astronomers are looking for a new Earth.
Space travel is nothing new.The first spaceship with a human was sent up _____ space in 1961.Since then,people have not only travelled to space,_____ many of them have also lived there in space stations for some time.
The Soviet Union(苏联)sent the _____ space station into space in 1971.This space station was called Salyut Ⅰ.It _____ as a place where people could live while they observed space and did experiments.The first group of astronauts lived there for 23 days.The Soviet Union went on to make seven more Salyut space stations.At about the same time,the United States had _____ own space station,called Skylab.
Astronauts _____ in these space stations for a short time.However,it wasn't until the late 1980s when the Soviet Union sent the Mir space station that people began to live in space for a _____ time.
Living in space stations seems to be fun,but astronauts face many problems.One of them _____ food.All the _____ on space stations are put together on Earth and sent there by spaceship.Because the food has to last a long time,a lot of it has to be stored in cans.The space station does not have a fridge,but it has a cool room to keep fruit and vegetables fresh.Astronauts also eat many other foods ______ dried meat that do not need special care.
1.A.into B.with C.of
2.A.for B.but C.unless
3.A.ones B.one C.first
4.A.was found B.was built C.was bought
5.A.them B.they C.its
6.A.lived B.played C.took
7.A.more B.shorter C.longer
8.A.am B.is C.are
9.A.apple B.vegetable C.meals
10.A.such as B.at last C.next to
