All of us face a variety of risks to our health in our daily life.Driving cars and being exposed to environmental pollutants all pose certain degrees of risk.Some risks would restrict our ability to lead a good life.And some are risks we might decide to avoid if we had the opportunity to make informed choices.Indoor air pollution is one risk that you can do something about.
Scientific evidence has indicated that the air within homes can be more seriously polluted than the outdoor air in even the most industrialized cities.Other research indicates that people spend approximately 90 percent of their time indoors.Thus,for many people,the risks to health may be greater due to exposure to air pollution indoors than outdoors.
In addition,people exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution.Such groups include kids,the elderly and the chronically ill,especially those suffering from respiratory disease.
While pollutant levels from individual sources may not pose a significant health risk by themselves,most homes have more than one source that contributes to indoor air pollution.There can be a serious risk from the cumulative effects of these sources.Fortunately,there are steps that most people can take both to reduce the risk from existing sources and to prevent new problems from occurring.This brochure was prepared by the U.S.Environmental Protection Agency（EPA）and the U.S.Consumer Product Safety Commission （CPSC）to help you decide whether to take action that can reduce the level of indoor air pollution in your own home.
Because so many Americans spend a lot of time in offices with mechanical heating and cooling systems,there is also a short section on the causes of poor air quality in offices and what you can do if you suspect that your office may have a problem.



Who will be exposed to indoor air pollution more often according to the text？ ______

A. A driver.
B. A housewife.
C. A farmer.
D. A cyclist.

What does the underlined word "susceptible" in paragraph 3 mean？ ______

A. Sensitive.
B. Essential.
C. Accustomed.
D. Familiar.

What can the brochure of EPA and CPSC help people do？ ______

A. Lead a healthier and richer life.
B. Throw individual things away.
C. Get rid of the risk of air pollution.
D. Reduce the risk of indoor air pollution.

What is the author's main purpose in writing the text？ ______

A. To show Americans' unhealthy lifestyle.
B. To stress the negative influence of pollution.
C. To tell people to reduce the time spent at home.
D. To remind people to take note of indoor air pollution.