On May 5, 2005, at _________ world Table Tennis Championship, Kong Linghui and Wang Hao won the gold medal in men’s doubles with ________ score of 4: 1.

A．a; a

B．不填; the

C．a; 不填

D．the; a

帧中继的虚电路是由多段DLCI的逻辑连接而构成的（）的逻辑信道。