It’s true that quite a few most respected scientific authorities have confirmed that the world is becoming hotter and hotter. There’s also strong evidence that humans are contributing to the warming. Countless recent reports have proved the same thing. For instance, a 2010 summary about the climate science by the Royal Society noted that: “The global warming over the last half-century has been caused mainly by human activity.”
You may not believe that humans could change the planet’s climate, but the basic science is well understood. Each year, billions of tons of greenhouse gases are released into the atmosphere because of human activity. As has been known for years, these gases hold heat that would otherwise escape to space, wrapping the planet in an invisible (看不见的) blanket.
Of course, the earth’s climate has always been changing due to “natural” factors such as volcanic eruption or changes in solar, or cycles concerning the Earth’s going around the sun. According to the scientific research, however, the warming observed by now matches the pattern of warming we would expect from a build-up of greenhouse gas in the atmosphere – not the warming we would expect from other possible causes.
Even if scientists did discover another reasonable explanation for the warming recorded so far, that would give birth to a difficult question. As Robert Henson puts it: “If some newly discovered factor is to blame for the climate change, then why aren’t carbon dioxide and the other greenhouse gases producing the warming that basic physics tells us they should be?”
The only way to prove with 100% certainty that humans are responsible for global warming would be to run an experiment with two identical Earths – one with human influence and one without. That obviously isn’t possible, and so most scientists are careful not to state human influence as an absolute certainty.
【小题1】In most scientists’ opinion, the global warming is mainly caused by ________.

It’s true that quite a few most respected scientific authorities have confirmed that the world is becoming hotter and hotter. There’s also strong evidence that humans are contributing to the warming. Countless recent reports have proved the same thing. For instance, a 2010 summary about the climate science by the Royal Society noted that: “The global warming over the last half-century has been caused mainly by human activity.”

You may not believe that humans could change the planet’s climate, but the basic science is well understood. Each year, billions of tons of greenhouse gases are released into the atmosphere because of human activity. As has been known for years, these gases hold heat that would otherwise escape to space, wrapping the planet in an invisible (看不见的) blanket.

Of course, the earth’s climate has always been changing due to “natural” factors such as volcanic eruption or changes in solar, or cycles concerning the Earth’s going around the sun. According to the scientific research, however, the warming observed by now matches the pattern of warming we would expect from a build-up of greenhouse gas in the atmosphere – not the warming we would expect from other possible causes.

Even if scientists did discover another reasonable explanation for the warming recorded so far, that would give birth to a difficult question. As Robert Henson puts it: “If some newly discovered factor is to blame for the climate change, then why aren’t carbon dioxide and the other greenhouse gases producing the warming that basic physics tells us they should be?”

The only way to prove with 100% certainty that humans are responsible for global warming would be to run an experiment with two identical Earths – one with human influence and one without. That obviously isn’t possible, and so most scientists are careful not to state human influence as an absolute certainty.

1.In most scientists’ opinion, the global warming is mainly caused by ________.

A．solar activity                           B．volcanic activity

C．natural factors                          D．human factors

2.The text is developed by ________.

A．giving typical examples

B．following the order of space

C．analyzing a theory and arguing it

D．comparing and finding differences

3.The underline word “identical” in the last paragraph probably means ________.

A．totally different                         B．exactly the same

C．extremely important                     D．partly independent

4.Which of the following is not the cause of climate change?

A．volcanic eruption

B．cycles concerning the Earth’s going around the sun

C．changes in solar

D．floods and droughts

5.Which of the following can be the best title?

A．Are All the Scientists Really Scientific?

B．Where Is Global Warming Leading Us to?

C．Are Humans Definitely Causing Global Warming?

D．What’s the Relation of Global Warming and Greenhouse Gases?

What science fiction once told of other worlds far away is now a fact. Astronomers prove another solar system like ours with some planets in the constellation (星座) Andromeda ( 仙女座).

Geoffrey Marcy is a professor of astronomy and physics at San Francisco State University and says, “What we have found now, for the first time ever, is indeed a fully-grown system of planets around the star Upsilon Andromeda. It appears to have three planets, one close in, one at a middle distance, and one farther out.” The star is slightly larger than our sun. The planets are huge, like our Jupiter(木星)

Marcy’s partner in this research, Debra Fischer, describes the solar system, “Here’s the inner planet that goes around every 46 days, the middle planet that goes around every 242 days, and then the outer planet that goes around every three and a half to four years.”

Astronomically, it’s not far away, 44 light years. The sun of that solar system, Upsilon Andromeda, is so near and bright that it can be seen by using no equipment during summer and fall.

For twelve years astronomers searched the skies in the belief that if our sun has planets around it, surely others do, too. Geoffrey Marcy says, “And then starting three and a half years ago, we began finding for the first time planets singly, one planet here around one star.”

“When I look up at the stars now at night, I can imagine easily that every one of them has planets around them,” says Debra Fischer.

It was a tremble in the star that led Marcy to the planets. “The star rocks around due to the gravity of the planet much like a dog owner gets pulled around by a little dog.”

Can they support life? We don’t know, because present technology is not advanced enough to determine what the planets are made of. “That,” Marcy says , “is astronomy’s next challenge.”

1. What’s the relation between Andromeda (A), Upsilon Andromeda system (U) and the mentioned planets (P) ?

2. According to Debra Fischer, in the new solar system, ________.

   A. the larger a planet is, the shorter it takes to go around the star.

   B. it takes all the planets around three and a half to four years to go around the star

   C. the planets move around the star at uneven speeds

   D. the farther a planet is from the star, the longer it takes to go around the star

3. What led to Marcy’s discovery of the planets?

   A. The tremble of Upsilon Andromeda.     

B. That any planet has gravity.

C. That he believes any star has its planets.  

D. that he found a dog owner was pulled by his dog.

4. We can infer that the scientists are           .

   A. to find means to communicate with the living beings on the planets

   B. to find means to travel to the planets

   C. soon to be able to answer the question of whether there is life on these planets

   D. to find out whether the planets can support life.

What science fiction once told of other worlds far away is now a fact. Astronomers prove another solar system like ours with some planets in the constellation (星座) Andromeda ( 仙女座).

Geoffrey Marcy is a professor of astronomy and physics at San Francisco State University and says, “What we have found now, for the first time ever, is indeed a fully-grown system of planets around the star Upsilon Andromeda. It appears to have three planets, one close in, one at a middle distance, and one farther out.” The star is slightly larger than our sun. The planets are huge, like our Jupiter(木星)

Marcy’s partner in this research, Debra Fischer, describes the solar system, “Here’s the inner planet that goes around every 46 days, the middle planet that goes around every 242 days, and then the outer planet that goes around every three and a half to four years.”

Astronomically, it’s not far away, 44 light years. The sun of that solar system, Upsilon Andromeda, is so near and bright that it can be seen by using no equipment during summer and fall.

For twelve years astronomers searched the skies in the belief that if our sun has planets around it, surely others do, too. Geoffrey Marcy says, “And then starting three and a half years ago, we began finding for the first time planets singly, one planet here around one star.”

“When I look up at the stars now at night, I can imagine easily that every one of them has planets around them,” says Debra Fischer.

It was a tremble in the star that led Marcy to the planets. “The star rocks around due to the gravity of the planet much like a dog owner gets pulled around by a little dog.”

Can they support life? We don’t know, because present technology is not advanced enough to determine what the planets are made of. “That,” Marcy says , “is astronomy’s next challenge.”

64. What’s the relation between Andromeda (A), Upsilon Andromeda system (U) and the mentioned planets (P) ?

65. According to Debra Fischer, in the new solar system, ________.

   A. the larger a planet is, the shorter it takes to go around the star.

   B. it takes all the planets around three and a half to four years to go around the star

   C. the planets move around the star at uneven speeds

   D. the farther a planet is from the star, the longer it takes to go around the star

66. What led to Marcy’s discovery of the planets?

   A. The tremble of Upsilon Andromeda.     

B. That any planet has gravity.

C. That he believes any star has its planets.  

D. that he found a dog owner was pulled by his dog.

67. We can infer that the scientists are           .

   A. to find means to communicate with the living beings on the planets

   B. to find means to travel to the planets

   C. soon to be able to answer the question of whether there is life on these planets

   D. to find out whether the planets can support life.