During exercise it is important to drink water even if you don't feel thirsty . a. true b. false

Which of these is most likely to prevent pregnancy? a. tracking of female body temperature to identify ovulation times b. proper condom use c. male withdrawal before ejaculation d. proper spermicide use

Blood cells bring oxygen to cells and take carbon dioxide away. true or false

Exercise has no positive effects on the nervous system? true or falseu