In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

[Q]: Diarrhea is an illness that kills _ and one-half million children per year.
[A]: three


[Q]: Echocardiography demonstrates in clear, graphic fashion the _ cardiac chambers and four valves.
[A]: four


[Q]: Barking frogs can live at least _ years as adults in the wild.
[A]:
six