Answer: Dealer; Brokers; electronic
Explanation: A dealer market is a financial market used to trade securities such as STOCKS,BONDS and other marketable securities,in this market,the dealers post the prices which they are willing to buy or sell but the orders are not automatically executed by the system.
Broker is an agent who facilitates trade execution rather than the people doing by themselves. Brokers are third parties.
Electronic markets are markets where computer matches orders and effectively execute the trade.