When is it acceptable to use the abbreviation PND?

How is health different for most people in this country today from what it was for people born in 1900? a. people have a shorter life span. b. people today work harder to survive. c. people today live in poorer sanitary conditions. d. people today can focus less on day-to-day survival and more quality of life.

Um yea this might be weird to say up here but me and my girl got freaky and shoved a bottle up my but thole and now is stuck. so what do i do?

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.