American doctors say that mothers who smoke cigarettes before their babies are born may slow the growth of their babies’ lungs. They say reduced lung growth could cause the babies to suffer breathing problems and lung disease later in life. Doctors in Boston, Massachusetts studied 1 100 children. The mothers of some of the children smoked, the other mothers did not. Doctors found that the lungs of the children whose mothers smoked were 8% less developed than the lungs of the children whose mothers did not smoke, and that the children whose mothers smoked developed 20% more cold and breathing diseases 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.
68. Mother who smokes before her child is born may _______.
A. slow the growth of her baby’s lung.
B. cause her baby to suffer breathing problems and lung disease later in life.
C. make her child develop lung cancer.
D. All of above are right.
69. Doctors in Boston studied 1 100 children to _______.
A. examine whether these children were healthy.
B. find out whether their mothers had smoked.
C. find why these children suffered breathing problems and lung disease.
D. look into the effect that mother’s smoking had on their children.
70. Suppose John’s father was a heavy smoker, so was Mary’s mother. According this passage, _______.
A. John is more likely to develop lung cancer.
B. Mary is more likely to develop lung cancer.
C. John and Mary have the same chance to develop cancer.
D. neither John nor Mary has the chance to develop cancer.
71. This passage is to _______.
A. warn us of the danger of smoking before children.
B. warn people with breathing problems not to smoke.
C. warn us that mothers who smoke may affect their children’s health.
D. warn us that fathers who smoke may affect their children as mothers.