A Bluetooth device can be either a master or a slave and any of the devices　within a 　（1）　 can be the master. There is only one master and there can be up to ?。?）　 active slave devices at a time within a single network. In addition，a device may be a standby slave or a parked slave. There can be up to 　（3）　 parked slaves. If there are already maximum number of active slaves, then a parked slave must wait until one of the active slaves switches to ?。?）　mode before it can become active. Within a network, all ?。?）　 communications are prohibited.
（1）A．Wireless LAN   
B．Wireless MAN
C．Cellular radio network  
D．Piconet
（2）A．7   
B．15    
C．63   
D．255
（3）A．127  
B．255   
C．511   
D．1023
（4）A．master      
B．standby slave
C．parked slave    
D．a(chǎn)ctive slave
（5）A．master-to-master   
B．master-to-slave
C．slave-to-slave    
D．slave-to-master