德国表现主义的第一个社团是（)。A．青骑士社B．《狂飙》杂志社C．桥社D．新客观社

A. SDH circuit over a SONET network delivering it as an SDH signal

B. SDH circuit over a SONET network delivering it as a SONET signal

C. SONET circuit over an SDH network delivering it as an SDH signal

D. SONET circuit over an SDH network delivering it as a SONET signal

A. the K1 SONET byte； the K2 SONET byte

B. the K2 SONET byte；the K1 SONET byte

C. transmitter switching；receiver detection

D. Line Overhead bytes；Path Overhead bytes

E. Path Overhead bytes；Line Overhead bytes

A.DUS

B.line timing

C.loop timing

D.internal timing

E.through timing

A．运用

B．ATM

C．数据链路层

D．网络层

ITU-T接受了SONET的概念，将其重新命名为

A．ATM

B．DDN

C．PDH

D．SDH