They use small depending on if you are in the in-feild or the out-feild out-field is bigger in fild smaller.
None.Usauly when you buy a light bulb the mesurment is already on there.
There is only one country which is the United States of America.
just use lambeau feild
use inches
Usually, you would use kilometers.
well i will give you a list of people who dont use football helmets. Hockey players, cheese makers, mechanics and so on..... Obviously a football player would use a FOOTBALL HELMET!!!
An odometer.
rectangle
It depends what you mean by "harder." foot ball is more physically damaging to the body. Hockey requires more stamina, since hockey players actually play more, where as footballers stand around alot when they're on the feild.
Neither. I would use a centimetre.
You could potentially use a ball for netball to play Gaelic Football, but it would not be ideal.