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

[EX Q]: Elk are more than _ times the size of deer.
[EX A]: three

[EX Q]: Air resistance is _ at zero velocity.
[EX A]: zero

[EX Q]: Most bats return to their roosts by four or _ o'clock in the morning.
[EX A]:
five