ack went to college last year, _______ to return home until he achieves his goal.

A．determined not

B．determining not

C．not determined

D．not determining

信号传输分配系统是一个信号电平的有限分配网络，它由（）组成。

A．分配器、线路放大器

B．分支器、传输电缆

C．探测器

D．用户终端器件