So a fuel injector will look something like this, except on the bike you will see some specifically electrical wires leading away and a few hoses.

A carb looks like this:


So the difference is: If you move the throttle grip, a throttle body on the carb will move if you have a carb. If you have FI then when you move the throttle grip nothing will move visibly. Also a fuel injector has electrical wires.

Also FI is so rare on Chinese motorcycles it will probably be written down the side of the bike!