填空题 American doctors say that mothers smoke before their 1
babies are born may slow the growth of their babies 2
lungs. They say reducing lung growth could cause 3
the babies suffer breathing problems and lung disease 4
late in life. Doctors in Boston studied 1,100 children. 5
The mothers of some of the children smoked; the other 6
Mothers did not. Doctor found out that the lungs of the 7
children whose mothers smoked were 8% less developed as 8
the children whose mothers did not smoke, that the 9
children whose mothers smoked were developed 20% more 10
cold and breathing diseases than the other children.