3. The cardiovascular system helps regulate body temperature by a. stimulating sweat production.
b. increasing the rate of metabolism.
C. controlling where blood flows in the body.
d. absorbing ultraviolet light through the skin.

*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