The three main functions of the human digestive system are to break food down into chyme for the body's use, to secrete and absorb nutrients and bodily fluids into the gastrointestinal tract or the blood, and to store and eliminate waste. The digestive system has major parts and accessory parts.
Answer:
nicotine
Explanation:
it is a highly addictive substance
It takes about 90 days so that the antibodies can get in action. This process is known as seroconversion and antibodies are not produced right after the person has been infected.
Answer:

Hope it helped,
Happy homework/ study/ exam!