单项选择题 某建材厂设计能力为年生产某型号预制构件7200件，每件售价5000元，该厂固定成本680万元，每件产品变动成本为3000元，则该厂的盈亏平衡产量为（ ）件。 A．3500 B．3000 C．4420 D．3400

未知题型 听力原文：Tens of thousands of youngsters from low-income families who were eligible for a children's health insurance program in Florida, instead of being allowed into the program, were diverted by state officials to a long waiting list.The children's health insurance program in Florida was intended to help kids from low-income families.A．正确B．错误

单项选择题 在以单利计息的情况下，总利息与本金、利率以及计息周期数（ ）。 A．相等 B．没有关系 C．成正比关系 D．成反比关系