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

[EX Q]: Falcons are roughly divisible into three or _ groups.
[EX A]: four

[EX Q]: Alcohol is high in calories - it supplies _ calories per gram and no nutrients worth mentioning.
[EX A]: seven

[EX Q]: Smoking causes ulcers by at least _ mechanisms.
[EX A]:
three