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

Q: Some bird feeders have _ perches at all, but neither do tree trunks.

A: no
****
Q: Echocardiography demonstrates in clear, graphic fashion the _ cardiac chambers and four valves.

A: four
****
Q: Ocelots are the most aquatic of the _ animals.

A:
four
****