单选题 Public-health concerns include—but are not limited to— issues such as smoking and secondhand smoke, substance abuse, and AIDS.
Smoking is a major health risk, since it is one of the top three risk factors for heart disease and stroke. Furthermore, spouses and co-workers of smokers share this danger, since their exposure to so-called "secondhand smoke" increases their risks for cancer, asthma, and respiratory infections. As a result, many employees have banned smoking from the workplace.
Substance abuse, including alcohol abuse, is a serious public-health problem in the United States. Motor vehicle accidents are a major killer, and drunk drivers cause many serious crashes. Alcohol abuse has also been linked to serious diseases such as cirrhosis of the liver. For these reasons, public opposition to alcohol advertising is steadily growing. Many consumers view both alcohol and tobacco advertising as socially irresponsible. Some brewers have tried to counter these views by sponsoring advertising campaigns that promote moderation.
AIDS represents a different type of challenge to business firms when dealing with the consequences of this terrible disease. AIDS is a fatal disease that breaks down the body's ability to defend itself against illness and infection. AIDS is especially dangerous because a long time (typically five years) elapses between someone's first exposure to the AIDS virus and actual development of the disease. During this period, people may not show any symptoms of AIDS, and they probably don't even know they have it, but they are still carriers who can give the disease to others. This large pool of unknown carriers accounts for the rapid spread of the disease. In 1982, only 1,013 cases of AIDS were reported; today the victims number over 200,000.
The rapid spread of AIDS has forced companies to educate their employees about it and to deal with employees who have the deadly disease. Health care for AIDS patients can be incredibly expensive, straining the ability of a small company to pay for health-care'coverage. Do companies have the right to test potential employees for the AIDS virus? Some people feel that this would violate the rights of job applicants; others feel that a firm has a responsibility not to place AIDS patients in jobs where they could infect members of the general public. These are difficult questions; in resolving them, a business must balance the rights of individuals against the rights of society in general.

单选题 According to the passage, smoking is a public-health concern because______.

单选题 Why is alcohol abuse a public-health concern?

单选题 Why, according to the passage, is AIDS a dangerous disease?

单选题 Companies don't like to employ people with AIDS because______.

单选题 In deciding whether to hire applicants with AIDS, a company has to______.