What do single celled and multicellular organisms have in common

Charlie is easily winded during soccer practice and wants to improve his cardiorespiratory fitness. which activity would be best for him to choose? lifting weights walking from one class to another running in a 5k race riding a bike at a leisurely pace

What type of medicine to people take if they are lactose intolerance

Check all that occur during ventricular systole. a. the av valves open to allow blood to enter the ventricles from the atria. b. the av valves open to allow blood to enter the ventricles from the atria. c. the semilunar valves remain closed throughout systole to prevent backflow of blood into the ventricles. d. the semilunar valves remain closed throughout systole to prevent backflow of blood into the ventricles. e. the semilunar valves open to allow blood to flow into the large arteries. f. the semilunar valves open to allow blood to flow into the large arteries. g. the av valves close to prevent backflow of blood into the atria.