What type of posture is described in the following statement? this type of posture occurs when you are performing work that causes you to hold the same posture or position for an extended period of time. working in such positions can restrict your blood flow and damage your muscles.

So i have a lot of answers answered but it says i still need to answer more questions. why is it doing that? how many questions need to be answered?

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.

The physician ordered velosef (cephradine) im 50 mg/kg/day in equally divided doses four times a day for a child who weighs 40 pounds. convert pounds to kilograms and then calculate the prescribed dosage. mg every hours