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

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


[Q]: Sediment consists of _ visually distinct floc layers.
[A]: two


[Q]: Mango trees begin fruit production in _ years and form fruit quickly.
[A]:
three