下列物质中不属于人体内环境组成成分的是( ) A. 葡萄糖 B. 细胞呼吸酶 C. 氧气 D. 神经递质 答案:BPlants are flowering faster than scientists predict 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 researchers 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 the speed
of flowering by 8.5 times and leafing by 4 times.
“Across all species, the experiments underestimated
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 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.
1.What is the key information the author wants to give
in Paragraph 1?
A. The increasing speed of flowering is beyond
scientists’ expectation.
B. Climate change leads to the change of food
production patterns.
C. Plants’ reaction to weather could have damaging
effects on ecosystem.
D. Food chains have been seriously damaged because of
weather.
2.We can learn from the study published on the Nature
website that _____.
A. scientists should improve the design of the
experiments
B. plants’ flowering is 8.5 times faster than leafing
C. there are 1,634 plant species on the four
continents
D. the experiments failed to predict how plants react
to climate change
3.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
4.What can be inferred from the last two paragraphs
about the world’s temperature?
A. It has risen nearly 0.2 ℃ since 1979.
B. It is 0.8 ℃ higher in
1979 than that of 1990.
C. It needs to be controlled within 2 ℃ in this
century.
D. Its change will lead to weather extremes.