1. [单选题]CU单板通过3个2mm连接器把()的信号连接到DCCU单板上
A. DEMU
B. DCMB
C. DTRU
D. DSAC
2. [单选题]指定逻辑通道备份主接口使用的命令是:( )
A. backup logic-channel number [ priority ]
B. backup interface interface-type interface-number
C. logic-channel logic-channel-number
D. dialer map protocol next-hop-address dialer-string [ lin logic-channel-number ]