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

Q: Porcine insulin has _ different amino acid and bovine insulin has three different amino acids.

A: one
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Q: Liquids usually descend in three to five seconds, and solids in _ to twenty seconds.

A: eight
****
Q: Sponges fall into _ main groups according to how their bodies are organized.

A:
three
****