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

Q: Muskrats are semi-aquatic and prefer locations with four to _ feet of water.

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

A: one
****
Q: Sewage travels through _ different sets of pipes.

A:
three
****