Which body system's main function is to fight infection and disease

How do nicotine and tobacco cause cancer? by decreasing blood-sugar levels by damaging or changing a cell's dna by increasing heart rate by increasing phlegm and mucous production

Why would a smoker tend to inhale more deeply and smoke more cigarettes when he or she switches to low nicotine cigarettes

Developing a positive identity to increase your level of self esteem true or false