Which system expels carbon dioxide from the body? excretory system digestive system cardiovascular system respiratory system

Which student is using a manipulative skill? a. megan is twisting. b. michelle is walking. c. tracy is dribbling a basketball. d. april is leaping.

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

Which of the following represents the results of a review of well-controlled studies of vitamin c supplementation on the resistance to, and recovery from, colds? there was a reduction in the duration of colds by 50% on the average. there was a slight effect on reducing the duration and severity of colds for people taking vitamin c supplements. there was a significant reduction in the duration of colds in people who consumed at least one gram a day. there was a significant reduction in the number of colds only in people who consumed > three grams per day.