单项选择题

Passage 2 　　Questions 6 to 10 are based on the following passage: 　　Onthejob smoking is a hot issue for both smokers and nonsmokers, and many managers now see smoking as a productivity problem. Although some people question whether smoking really affects one’s productivity, it has, in fact, been proven that a smoker costs a company more than a nonsmoker. According to Professor William Weis, a smoking employee costs his or her employer about $ 5,700 more a year than a neversmoker. These costs include medical care, lost earnings and insurance. And absence due to smoking breaks is one of the productivity problems, yet it accounts for a great deal of employer costs. 　　(78) When the issue of smoking at the workplace is discussed, perhaps the most important problem is the health risk that smoking causes to both smokers and neversmokers. It has long been proven that smoking is linked to lung cancer. Now many health experts warn that passive smoking can cause lung cancer and other illnesses in healthy neversmokers. Passive smoking can be defined as exposure to secondhand tobacco smoke in enclosed areas. Anyone who has been with smokers indeed knows that their smoke can cause eye irritation, coughing, headaches and throat soreness. While eye irritation may seem a small thing to some smokers, it nevertheless is a problem that occurs every workday in offices and breakrooms and can lead to greater health problems. Employees who do not smoke should not be subjected to the risks of passive smoking and need to be able to work in a safe environment. Surgeon General Koop states that the right of the smoker stops at the point where his or her smoking increases the disease risk of those occupying the same environment. In the second part of the passage, the author suggests banning onthejob smoking so as to____.