foot is one feet is more than one
yes
Yes, because more than one virus can cause it.
Sure. It has more than one meaning. That makes it eligible for punning. "My socks are all one foot long."
yes one foot is bigger than the other
For the same length, the number in feet is less than the number in inches. As a unit, a foot is bigger than one inch; as 1 foot = 12 inches.
they can be a small as a couple inches and as big a little more than one foot
One foot.
Two times longer than one foot
No.
YES ... there are 12 inches in a foot.
The height of a grown man is about six "feet". "Foot" is the singular form, more than one is "feet".