Conversation so far:
where must a throw in be taken from
The throw-in is taken from the point where the ball crossed the touch-line, either on the ground or in the air.
what sports are throw-ins from
A throw-in is a method of restarting play in a game of football (or soccer) when the ball has exited the side of the field of play.

Question: what kind of ball is used
Self-contained rewrite: what kind of ball is used in soccer