Still waiting for little green men to make contact? Don't hold your breath.
A leading astronomer has concluded there probably aren't any aliens out there – meaning we are absolutely alone in the universe.
Even though there may be tens of thousands of other distant planets similar in size to Earth, the conditions on them are likely to be too hard to support life-forms such as ET.
Dr Howard Smith, a senior astrophysicist at Harvard University, believes there is very little hope of discovering aliens and, even if we did, it would be almost impossible to make contact.
So far astronomers have discovered a total of 500 planets in distant solar systems – known as extrasolar systems – although they believe billions of others exist.
But Dr Smith points out that many of these planets are either too close to the sun or too far away, meaning their surface temperatures are so bad that they could not support life. Others have unusual orbits which cause vast temperature variations, making it impossible for water to exist – the most important thing for life.
Dr Smith said, "We have found that most other planets and solar systems are wildly different from our own. It means it is highly unlikely there are any planets with intelligent life close enough for us to make contact." But his suggestions contradict other leading scientists who have claimed aliens almost certainly exist.
Only last month Professor Stephen Hawking said the fact that there are billions of galaxies out there made it reasonable to think there were other life-forms in the universe.
Researchers from the University of London have recently suggested that aliens could be living on as many as 40,000 other planets. But Dr Smith said: "Any hope of contact has to be limited to a relatively tiny space around the Earth, reaching maybe 1,250 light years out from our planet, where aliens might be able to pick up our signals or send us their own. But communicating would still take decades or centuries."
【小题1】By saying ＂don’t hold your breath＂, the author advised the reader not to _____.

Still waiting for little green men to make contact? Don't hold your breath.

A leading astronomer has concluded there probably aren't any aliens out there – meaning we are absolutely alone in the universe.

Even though there may be tens of thousands of other distant planets similar in size to Earth, the conditions on them are likely to be too hard to support life-forms such as ET.

Dr Howard Smith, a senior astrophysicist at Harvard University, believes there is very little hope of discovering aliens and, even if we did, it would be almost impossible to make contact.

So far astronomers have discovered a total of 500 planets in distant solar systems – known as extrasolar systems – although they believe billions of others exist.

But Dr Smith points out that many of these planets are either too close to the sun or too far away, meaning their surface temperatures are so bad that they could not support life. Others have unusual orbits which cause vast temperature variations, making it impossible for water to exist – the most important thing for life.

Dr Smith said, "We have found that most other planets and solar systems are wildly different from our own. It means it is highly unlikely there are any planets with intelligent life close enough for us to make contact." But his suggestions contradict other leading scientists who have claimed aliens almost certainly exist.

Only last month Professor Stephen Hawking said the fact that there are billions of galaxies out there made it reasonable to think there were other life-forms in the universe.

Researchers from the University of London have recently suggested that aliens could be living on as many as 40,000 other planets. But Dr Smith said: "Any hope of contact has to be limited to a relatively tiny space around the Earth, reaching maybe 1,250 light years out from our planet, where aliens might be able to pick up our signals or send us their own. But communicating would still take decades or centuries."

1.By saying ＂don’t hold your breath＂, the author advised the reader not to _____.

A．keep silent        B．give up           C．expect so         D．be afraid

2.Dr Smith concludes there probably aren’t any aliens because other planets _____.

A．are too far away from the earth

B．are different from the Earth in size

C．don’t have rich natural resources

D．don’t have a suitable living environment

3.Researchers from the University of London are mentioned to show that ______.

A．they have better explanations about aliens

B．aliens certainly exist on many planets

C．they disagree with Dr Smith’s suggestion

D．aliens can pick up signals from the earth

4.What’s the main idea of the text?

A．There must be other life forms in the universe.

B．We can communicate with aliens in decades.

C．The chances of finding aliens are slight.

D．Many other planets are quite different from the Earth.

       "Have you ever been out on a boat and felt it lifted up by a wave? Or have you jumped in the

water and felt the rush of energy as waves came over you?" asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh．"There is certainly a lot of energy in waves," he said．Scientists are working to use that energy to make electricity．Most waves are created when

winds blow across the ocean．"The wind starts out by making little ripples (涟漪) , but if they

keep on blowing, those ripples get bigger and bigger and turn into waves," Taylor said．" Waves

are one of nature 's ways of picking up energy and then sending it off on a journey.

       When waves come toward the shore, people can set up dams to block the water and send it

through a large wheel called a turbine (涡轮机) ．The turbine can then power an electrical
generator to produce electricity .

       "The resource is huge," said Janet Swain of the World watch Institute．"We will never run out of wave power．" Besides, wave energy does not create the same pollution as other energy sources, such as oil or coal．Oceans cover three-quarters of the Earth's surface - that would make wave power seem ideal for creating energy throughout the world, though there are some weak points yet to overcome．

       Swain said that wave power still costs too much money．She also said that its effects on sea animals are still unknown．What is more, wave power could affect fishing and boat traffic.

       Traditional sources of energy like oil and gas may someday run out．" Demand for energy to

power our TVs and computers, drive our cars, and heat and cool our homes is rising rapidly throughout the world," Swain said．In the future when you turn on a light, an ocean wave could be

providing the electricity!

64．The writer uses the two questions at the beginning of the passage to _______.

       A．test the readers' knowledge about waves

       B．draw the readers' attention to the topic

       C．show Jamie Taylor's importance

       D．invite the readers to answer them
65．The underlined phrase "picking up" (paragraph 2) is closest in meaning to _______.

       A．starting again       B．speeding up         C．gathering             D．improving
66．We can make better use of wave energy if we _______.

       A．shorten its journey to thousands of homes

       B．build more small power stations on the oceans

       C．reduce the cost of turning it into electric power

       D．quicken the steps of producing electricity

67．It can be inferred that some day we might not worry about ________.

       A．air pollution                                         B．our boat traffic    

       C．our power supply                                D．our supply of sea fish

"Have you ever been out on a boat and felt it lifted up by a wave? Or have you jumped in the water and felt the rush of energy as waves came over you?" asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh．"There is certainly a lot of energy in waves," he said.

Scientists are working to use that energy to make electricity．Most waves are created when winds blow across the ocean．"The wind starts out by making little ripples （涟漪）, but if they keep on blowing, those ripples get bigger and bigger and turn into waves," Taylor said. "Waves are one of nature's ways of picking up energy and then sending it off on a journey．"

When waves come toward the shore, people can set up darns to block the water and send it through a large wheel called a turbine （涡轮机）．The turbine can then power an electrical generator to produce electricity．

"The resource is huge," said Janet Swain of the World Watch Institute．"We will never run out of wave power．"Besides, wave energy does not create the same

pollution as other energy sources, such as oil or coal．Oceans cover three-quarters of the Earth's surface that would make wave power seem ideal for creating energy throughout the world, though there are some weak points yet to overcome．

    Swain said that wave power still costs too much money．She also said that its effects on sea animals are still unknown．What is more, wave power could affect fishing and boat traffic.

    Traditional sources of energy like oil and gas may someday run out．"Demand for energy to power our TVs and computers, drive our cars, and heat and cool our homes is rising rapidly throughout the world," Swain said. In the future when you turn on a light, an ocean wave could be providing the electricity!

1．The writer uses the two questions at the beginning of the passage to ____．

A．test the readers' knowledge about waves

     B．draw the readers' attention to the topic

     C．show Jamie Taylor's importance

     D．invite the readers to answer them

2．The underlined phrase "picking up" （paragraph 2） is closest in meaning to ____．

     A．starting again                                    B．speeding up

       C．gathering                                        D．improving

3．We can make better use of wave energy if we ____．

       A．shorten its journey to thousands of homes

      B．build more small power stations on the oceans

      C．reduce the cost of turning it into electric power

      D．quicken the steps of producing electricity

4．It can be inferred that some day we might not worry about ____．

      A．air pollution                                         B．our boat traffic

      C．our power supply                                D．our supply of sea fish