article: Young people should be enjoying the best time of their lives . but those in their twenties or thirties are in worse health than their parents ,a British survey has found .
  Drinking too much , eating fast food and being  _ short of _ exercise  all have a bad influence on young people .As a result , the young are more likely to have headaches , catch colds or become stressed than their parents .
  According to the survey , those aged between 18 and 34 are three times more likely to catch colds than the older people . The following are the main reasons .
  The old people usually eat more healthily .More than four in ten old people eat five or more part of fruit or vegetables a day . It's twice the number of the young men and woman .  Six in ten old people cook their own meals every day .., compared to less than one third of the young people . Almost 10% of the young people admit that they eat fast food for every meal and 2% say they only eat at restaurants .
  The old people are also more likely to take a lot of exercise . 12% of them spend at 30 minutes doing exercise each day .  They are healthier .  However ,only 9% of the young do so .
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question: Among the old people ,  _  in   100 usually have meals at home .
options: 10 30 40 60