单项选择题
| 请根据下面的短文回答第66-70题 American doctors say that mothers who smoke before their babies are born may slow the growth of their babies’ lungs. They say reduced lung growth could cause the babies to have breathing problems and lung illness later in life. Doctors in Boston, Massachusetts studied 1,000 children. The mothers of some of the children smoked, the other mothers did not. Doctors found that the lungs of the children whose mother smoked were 8% less developed than the children whose mothers did not smoke, and that the children whose mothers smoked developed 20% more cold and breathing illness than other children later in life. Another recent study found that children had a greater chance of developing lung cancer if their mothers smoked. The study also showed that the danger of lung cancer increased only for sons and not for daughters, and that the father’s smoking did not affect a child’s chance of developing lung cancer. |