Doctor Terry Pechacek at the C.D.C. says the findings should persuade every country that smoking in enclosed spaces is very dangerous to nonsmokers.

• 疾控中心的TerryPechacek博士说，这些研究结果应该提醒每一个国家，在密闭环境中吸烟对于不吸烟者来说是非常危险的。