what is bound to happen to the world in a million year pls dont report this question i jus had this question for so many years btw

If a person has a bad pain in their back, specifically lower back a bit above the hip, what should they do besides going to the doctor? what remedies could they use?

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.

Control center is it involved in homeostasis