The brain gets used to you taking the drug. Some drugs will affect your neurotransmitters, or messages that get sent to your brain that regulates how we think or feel. You will eventually become dependent on the drug so if you stop you might feel sick or go through "withdrawal". Which people dont want to go through so they will continue to take the drug.
Answer:
nausea and vomitting and blood in his stool
B. Heart, Chambers
Heart pumps blood to your body and it has four chambers.
Hope this helps.
