The National Assembly elects from among its members Standing and Ad hoc Committees.The Standing Committees assist the activity of the National Assembly and exercise on its behalf parliamentary control.The Ad hoc Committees are elected on a particular occasion to investigate specific matters and to conduct inquiries. The Committees consider bills, draft resolutions, declarations and addresses, and prepare reports, make recommendations and give opinions thereon. Committee meetings allow for participation representatives of state, industrial or public organisations, scientists and experts besides the movers of the bills. The National Assembly may alter the type, number and composition of the Standing Committees. The composition of the Standing Committees is based on the principle of proportional representation of the Parliamentary Groups.