2012年高考英语四川卷含答案

D. It is a new kind of free online course of Harvard and MIT.

E

Plants are flowering faster than scientists predicted（预测）in reaction to climate change,

which could have long damaging effects on food chains and ecosystems.

Global warming is having a great effect on hundreds of plant and animal species around the

world, changing some living patterns, scientists say.

Increased carbon dioxide（CO2）in the air from burning coal and oil can have an effect on

how plants produce oxygen, while higher temperatures and changeable rainfall patterns can

change their patterns of growth.

“Predicting species’ reaction to climate change is a major challenge in ecology,” said the

researches of several U.S. universities. They said plants had been the key object of study because

their reaction to climate change could have an effect on food chains and ecosystem services.

The study, published on the Nature website, uses the findings from plant life cycle studies

and experiments across four continents and 1,634 species. It found that some experiments had

underestimated（低估）the speed of flowering by 8.5 times and leafing by 4 times.

“Across all species, the experiments under-predicted the speed of the advance — for both

leafing and flowering — that results from temperature increases,” the study said.

The design of future experiments may need to be improved to better predict how plants will

react to climate change, it said.

Plants are necessary for life on the Earth. They are the base of the food chain, using

photosynthesis（光合作用）to produce sugar from carbon dioxide and water. They let out oxygen

which is needed by nearly every organism on the planet.

Scientists believe the world’s average temperature has risen by about 0.8℃ since 1900, and

nearly 0.2℃ every ten years since 1979.

So far, efforts to cut emissions（排放）of planet-warming greenhouse gases are not seen as

enough to prevent the Earth heating up beyond 2℃ this century — a point scientists say will

bring the danger of a changeable climate in which weather extremes are common, leading to

drought, floods, crop failures and rising sea levels.

57. What is the key information the author wants to give in Paragraph 1?

A. Plants’ reaction to weather could have damaging effects on ecosystem.

B. The increasing speed of flowering is beyond scientists’ expectation.

C. Climate change leads to the change of food production patterns.

D. Food chains have been seriously damaged because of weather.

58. We can learn from the study published on the Nature website that ______.

A. plants’ flowering is 8.5 times faster than leafing

B. there are 1,634 plant species on the four continents

C. scientists should improve the design of the experiments

D. the experiments failed to predict how plants react to climate change

59. Scientists pay special attention to the study of plants because _______.

A. they can prove the climate change clearly

B. they are very important in the food chains

C. they play a leading role in reducing global warming

D. they are growing and flowering much faster than before

60. What can be inferred from the last two paragraphs about the world’s temperature?