揭示了医学科研道德的思想性内涵（） A.20世纪50年代西欧研制的药物"反应停"，既

急性失血性贫血患者，当丢失血容量至少达多少时即可有贫血表现

A．10%

B．20%

C．25%

D．30%

E．35%

函数y=|x-1|（-1≤x≤2）与y=1/2x+m的图像有两个交点，则m的取值范围（）

氧气瓶外表须漆成（），并用黑漆写明“氧气”字样。

A、黄色

B、白色

C、灰色

D、天蓝色

阅读理解。

     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.

1. 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.

2. 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

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. Its change will lead to weather extremes.

C. It is 0.8? higher in 1979 than that of 1990.

D. It needs to be controlled within 2? in this century.

挤出生产线需要哪些基本设备？工艺控制有哪些因素？