问题 选择题

过氧化氢(H2O2)俗名“双氧水”,是隐形眼镜的洗液成分,下列有关叙述正确的是(  )

A.它与水的化学性质相同

B.每个分子由2个氢元素和2个氧元素组成

C.它由1个氧分子和1个氢分子构成

D.它与水的组成元素相同

答案

A、过氧化氢与水的分子构成不同,因此它与水的化学性质不相同,故A错误;

B、每个过氧化氢分子是由2个氢原子和2个氧原子构成的,且元素不讲个数,故B错误;

C、分子直接构成物质,则过氧化氢是由过氧化氢分子直接构成的,故C错误;

D、由化学式可知过氧化氢是由氢元素和氧元素组成的,与水的组成元素相同,故D正确.

故选D.

阅读理解

Cutting global warming pollution would not only make the planet healthier, it would make people healthier too, new research suggests.

Cutting carbon dioxide emissions could save millions of lives, mostly by reducing preventable deaths from heart and lung diseases, according to studies released Wednesday and published in a special issue of The Lancet British medical journal.

“Relying on fossil fuels leads to unhealthy lifestyles, increasing our chances for getting sick and in some cases takes years from our lives,” US Health and Human Services Secretary Kathleen Sebelius said in a telecast (电视广播) briefing from her home state of Kansas. “As greenhouse gas emissions go down, so do deaths from cardiovascular (心血管的) and respiratory diseases (呼吸疾病). This is not a small effect.”

Instead of looking at the health ills caused by future global warming, as past studies have done, this research looks at the immediate benefits of doing something about the problem, said Linda Birnbaum, director of the US National Institute of Environmental Health Sciences.

Some possible benefits seemed highly speculative (投机的,推测的), the researchers conceded (承认,给予), based on people driving less and walking and cycling more. Other proposals studied were more concrete and achievable, such as reducing cook stoves that burn dung (粪便), charcoal and other polluting fuels in the developing world.

And cutting carbon dioxide emissions also makes the air cleaner, reducing lung damage for millions of people, doctors said.

“Here are ways you can attack major health problems at the same time as dealing with climate change," said lead author Dr. Paul Wilkinson, an environmental epidemiologist at the London School of Hygiene and Tropical Medicine.

Wilkinson said the individual studies came up with numbers of premature deaths prevented or extra years of life added for certain places.

For example, switching to low-polluting cars in London and Delhi, India, would save 160 lost years of life in London and nearly 1,700 in Delhi for every million residents, one study found. But if people also drove less and walked or biked more, those extra saved years would soar (高耸,高涨) to more than 7,300 years in London and 12,500 years in Delhi because of less heart disease.

小题1:What does the passage mainly about?

A.How can people live longer.

B.Cutting carbon dioxide emissions saves life.

C.Global warming threatens people’s lives

D.People should stop relying on fossil fuels小题2:The new research differs from past studies in that ________.

A.it focuses on the immediate benefits of cutting carbon dioxide emissions

B.it studies the bad effects arising from future global warming

C.it is believed by most people

D.it mainly targets at developing countries小题3:According to Kathleen Sebelius ________.

A.sometimes it takes years to see the bad effects caused by consuming fossil fuels

B.without greenhouse gas emissions, people would not die of cardiovascular and respiratory diseases

C.the main reason why people get sick is that they rely on fossil fuels

D.death from cardiovascular and respiratory diseases are closely related to greenhouse gas emissions小题4:It can be inferred from the passage that ________.

A.London and Delhi have already benefited from reducing greenhouse gas emissions

B.switching to low-polluting cars would save 160 lives in London every year

C.walking and biking instead of driving will reduce the chance of heart disease

D.attacking health problems and dealing with climate change are contradictory

单项选择题 A型题