Teenagers who do not get enough of the nutrients commonly found in fruits and fish are easier to have bad lungs, coughing and wheezing （喘息）．Teens who eat the least of fruit and especially vitamin C have weaker lungs compared to the others．
Teens who take in less vitamin E, found in vegetable oil and nuts, are more likely to have asthma（哮喘）, Jane Bums at the Harvard School of Public Health found.
Based on these findings．Bums said that current recommended dose（一剂）of vitamin C, 85 mg a day, may not be enough for teens to have healthy lungs．Teens who eat less fruit and don't take in enough fatty acids （脂肪酸） are more likely to have asthma and the signs of breathing difficulty．
Proper amounts of fatty acids are protective, Bums said, though fish, the best source of fatty acids, is particularly unpopular with teenagers．Fatty acids are also found in some nuts as well as some green vegetables'．Smokers who avoid vitamin C will increase their chances of coughing, wheezing and developing phlegm（痰）．
More than 80 percent of teens are getting their recommended doses of vitamin C - mainly from fruit drinks．"I wouldn't approve of drinking them, but at least they're getting their vitamin C from somewhere," Burns said．
Burns added that there are several different ways to get the necessary nutrients．"I think vitamin supplements are fine．I think adding vitamin D to orange juice is fine．But I do think there are added benefits that we don't fully understand of eating whole foods like fruits and vegetables and fish," she said．The researchers did not account for poverty and other factors that often distinguish less-healthy eaters and may explain their findings．
小题1:According to the passage, what is the problem with teens who don't get enough nutrients?
A．They are becoming smokers．
B．They don't take enough exercise．
C．They eat too much fruit and fish．
D．They are likely to have weaker lungs．小题2:According to Burns, how should teens get the necessary nutrients?
A．By drinking juice as much as possible．
B．By eating more whole foods．
C．By taking vitamin pills．
D．By giving up smoking．小题3:Which of the following is NOT mentioned by the researchers in the passage?
A．The amount of nutrients teens should take in a day．
B．How teens can take in enough nutrients．
C．Whether poor teens can prove their findings．
D．The fact that teens don't like fish．小题4:What is the best title for the passage?
A．Poor nutrition hurts teens' health．
B．Teens lack proper nutrition．
C．Teens are easy to suffer from diseases．
D．More fruit help keep teens healthy．