we should do sports every morning or every evening and often open windows to keep the air fresh. wash our hands often,especially before meals and have healthy food and drink enough water every day. we shouldn't spit everywhere. if everyone has a good habit, we would keep fit.
do you want to be healthy? do morningexercises for half an hour or forty minutes every day. wash your hands before each meal and open windows very often even though in winter. fresh air is good for you. don't spit everywhere.
i have another idea. don't overwork. too much work will be bad for you.