A good idea what one could do in the off-season (considering one would do seasonal sports such as skiing) would be to either engange in activities that will preserve fitness - b, or to relax and recuperate; depending on the desire and wishes of the person - a.
Answer: They are highly communicable (spread from person to person)
Explanation: Not all STDs are curable most can get meds that make the symptoms not as but they will not cure the person. They do not always have symptoms some do not know they have it till testing has been done. They cannot spread through casual contact, sexual intercourse, oral, or kissing needs to happen. they are highly communicable because they can be passed from person to person through their methods of being passed.
The answer would be enzyme because vitamin D is a protein enzyme
