⑴ 模拟取号机的功能，减少排队中带来的麻烦； ⑵ 模拟银行取号的过程，加深对排队叫号机原理的认识；(The simulation of the take-a-number machine function, reduce queuing in trouble; The simulation process of bank, deepen understanding of the principle of the line numbering machine;)