One habit to avoid in order to keep your body systems healthy is eating a well-balanced meal. exercising. using illegal drugs. sleeping seven hours a night.

Is this a true of false question.  You don't want to avoid eating well balanced meals and you should sleep about 8 hours a night.  The only habit to avoid is obviously drugs. 

Clean air provides nitrogen

Taking a shower. why is cause as you shower the water is running more than taking a bath, washing a load of dishes or brushing your teeth. water is being used more by taking a shower and depending on how many people live in the household that take showers. some take a shower twice a day.