I'm bored someone talk to me.

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

*edit* i took the test and i picked a and it was incorrect for its c! rank the following suggestions for preventing std, in order of increasing effectiveness. 1) using latex condoms properly 2) using spermicidal foam or jelly with a monogamous partner 3) abstaining from sexual intercourse and genital contact a. 1, 2, 3c. 2, 1, 3

Why mature red blood cells has no nucleus