患者恶寒一日，伴头痛，身痛，无汗，鼻塞，舌苔薄白，脉浮紧。其病因为
A．寒邪B．暑邪C．湿邪D．痰饮E．以上均非
参考答案：A
Both bus and tree topologies are characterized by the use of multipoint(1)．For the bus,all stations attach,through appropriate hardware(2) known as a tap,directly to a linear transmission medium, or bus. Full-duplex operation between the station and the tap allows data to be transmitted onto the bus and received from the(3).Atransmission from any station propagates the length of the medium in both directions and can be received by all other(4).At each end ofthe bus is a(5),which absorbs any signal, removing it from the bus．
空白（1）处应选择（）
A.medium
B.connection
C.token
D.resource
设方程组有唯一解，则（）。
A．a=2
B．a≠2
C．a=-1
D．a≠1
有唯一解，则（）。