fuel line-fill line
Sure you can, but I usually empty the tank through the carb line.
The clunk screen catches any stuff and for my planes it's easier to reach than the carb line, than flipping the plane over on it's back and using the fill line.
It's a personal choice, but I think I've gotten better consistency in filling the tanks with the tube in the bubble top of the tank, above the fuel "surface" at full.