Which is not a symptom of peptic ulcers?
a. gnawing pain in the abdomen
b. nausea
c. gangrene
d. loss of appetite

Which of the following can be effective in preventing the onset of viral infection in humans? a) taking vitaminsb) getting vaccinatedc) taking antibioticsd) taking drugs that inhibit transcription

Results from damage to tiny air sacs in the lungs

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.