John really wants to become a doctor. he continues working toward his goal, despite the fact that he has trouble with the course work and has difficulty getting admitted to college and paying for his education. john's willingness to keep working toward his goal, despite the setbacks, is an indication that john hasa. grit. b. external motivation. c. internal motivation. d. natural talent.

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.