Some scientists believe that Mars is the planet with the highest chance of supporting human life away from Earth.
They believe that it’s possible for human to reach Mars by 2030. However, there are many things to prepare before this can happen.
Putting people on Mars will include (包括) planning how a person will live on Mars. At its shortest distance, Mars is 55 million kilometers away from Earth.
根据材料内容，从下面五个选项中选出能填入文中空缺处的最佳选项，使短文意思通顺，内容完整。
| A．Astronauts have been the key to the plan. |
| B．For example, they had to be fed with bad food. |
| C．One day humans will be able to live on Mars. |
| D．Scientists must make some research on Mars well. |
| E．So it would take about 6 months for a one-way trip. |
相似题推荐
【推荐1】In 2080, the Earth is dying, and moving to Mars seems to be the only way out for mankind. A team of American astronauts begin to search on Mars. This is what the movie Red Planet begins with. Known as Red Planet Mars is popular with science fiction(小说) writers and filmmakers.
Mars is the fourth planet from the Sun. We can see the surface of Mars from the Earth. It is half the size of our planet. The rocks, soil and sky have a red or pink hue(色调). The red color was observed by star-gazers throughout history. The ancient Romans named the planet “Mars” after their god of war because of its red color. The ancient Egyptians named it “Her Descher” meaning the red one.
The surface of Mars is more like the Earth than any other planet. However, because it is farther from the Sun than the Earth, temperatures on Mars are much lower. Most of the time the temperatures are far below freezing. The average temperature on Mars is -63℃ with a highest temperature of 20℃ and a lowest of -140℃. Plants and animals could not live now on Mars.
However, many scientists believe that such life may have existed long ago. On 6th August, 1996, scientists discovered a piece of rock from Mars. It fell to the Earth 13,000 years ago, and evidence of simple fossil creatures has been found in it. However, some scientists still don’t accept that there was life on Mars. People may not be so sure about life on Mars until a sample(样本)of life is brought back
1. What is the first paragraph mainly about?| A．The astronauts doing search on Mars. | B．A movie about Mars. |
| C．The history of Mars. | D．The future of mankind living on Mars |
| A．Because Mars is a good name. | B．Because its surface is like the Earth. |
| C．Because the color of Mars is red. | D．Because the ancient Romans liked their god of war |
| A．Mars is smaller in size than the Earth. | B．Mars is closer to the Sun than the Earth |
| C．It is warmer on Mars than on the Earth. | D．There is life on Mars. |
| A．Mars. | B．The Earth. | C．A piece of rock | D．Evidence of fossil creatures. |
| A．Culture. | B．Sports. | C．Science. | D．Environment. |
A comet sometimes looks like a star. Like a planet, a comet has no light of its own. It shines from the sunlight it reflects (反射). Like the earth a comet goes around the sun, but on a much longer path than the earth travels.
If a comet isn’t a star, what is it then?
Some scientists think that a large part of a comet is water frozen (冻) into pieces of ice and mixed with iron and rock dust and perhaps a few big pieces of rock. When sunshine melts (融化) the ice in the comet, great clouds of gas go trailing after it. These clouds, together with the dust, form a long tail.
Many people have seen a comet. However, no one knows how many comets there are. There may be millions of comets, but only a few come close enough for us to see.
An Englishman named Edmund Halley, who lived from 1656 to 1742, found out a lot about the paths that comets take through the sky. Some comets move out of our sight and never come back. Others keep coming back at regular times. A big comet that keeps coming back was named after Halley comet, because the last time it came close to the sun and the earth was in the year 1986. Then people all over the world were outside at night to look at it. You will probably be able to see Halley’s comet when it comes near the earth again.
根据短文内容，从题中所给的A、B、C、D四个选项中，选择最佳答案。
1. A comet is like.
| A．the sun | B．the moon |
| C．sunlight | D．the earth |
| A．water and rock |
| B．water frozen into pieces of ice and mixed with iron and rock dust and perhaps a few pieces of rock |
| C．ice, iron and rock dust |
| D．only a few big pieces of rock |
| A．haven’t seen any comets |
| B．have seen all comets |
| C．have seen a comet at daytime |
| D．have seen a comet |
| A．at any time |
| B．at noon |
| C．at regular times |
| D．at daybreak (拂晓) |
| A．In 1656. | B．In 1742. |
| C．In 1986. | D．In 1996. |
【推荐3】One of the most detailed descriptions of a UFO was given by nine-year-old Gaynor Sunderland in July 1976. Gaynor lived in Oakenholt, a village in North Wales. On her way home from school, she saw a silver object shaped like a saucer (茶碟) in a field not far from her home.
The strange craft (飞行物) was about 30 feet long and 9 feet high. It had yellow windows along the side and on the top there was a light flashing in a kind of box. Although Gaynor was very frightened, she did not run away. Instead, she lay quietly in the long grass and watched the door of the strange craft open. She saw two people wearing silver suits come out of the craft. They were carrying some kind of equipment (设备) which they used to examine the ground. They were short and had large pink eyes, Gaynor reported.
After about half an hour, the two people went back into the craft. At once there was a loud noise and the UFO took off.
Although Gaynor told her mother what she had seen, her family decided to keep quiet about it. They did not want people to laugh at their daughter. However, 18 months later, Gaynor told her story to UFO experts. They hypnotized (使人进入睡眠状态) Gaynor so that they could be sure she was telling the truth.
Not only did she repeat her story, but also she was able to draw a picture of what she had seen!
1. Which of these descriptions of Gaynor is true?| A．She’s nine, lives in a village and has never seen a UFO before. |
| B．She was nine, and lived in Sunderland in England in 1976. |
| C．She was nineteen in July 1986, and lived in North Wales as a child. |
| D．She was at school north of Wales and her family name was Oakenholt. |
| A．It was round and flat, and had yellow windows along the side. |
| B．It was ten feet longer than its breadth, and was silver. |
| C．It was a saucer-shaped box about thirty feet high. |
| D．It was a strange silver saucer which was like a craft. |
| A．She told her mother. | B．She ran away. |
| C．She went home from school. | D．She hid in the long grass and watched it. |
| A．UFO experts. | B．Two short, pink-eyed people. |
| C．Two astronauts. | D．Silver people with equipment. |
| A．She had been lying about the UFO. | B．She didn’t understand the UFO. |
| C．She told what she saw about the UFO to the experts. | D．She couldn’t speak but she could draw a picture of the UFO. |
