Managed care includes: A: Capitation-based reimbursement B: Health Maintenance Organizations (HMOs) C: Preferred Provider Organizations (PPOs) D: Point-of-service (POS)

一台多用户微机的串行通信接口内含Intel 8251A、MC1 488及MC1 489芯片，主机与汉字终端之间通过直接连接实现通信，则终端所接收到的信号电平为 A: TTL B: RS232C C: CMOS D: HMOS