When he arrived at the airport, Lee Minho found that            fans were waiting for him there.

A．hundred

B．hundreds

C．hundred of

D．hundreds of

TCP/IP协议集的参考模型层次有 (23) 。TCP/IP协议集中的UDP协议提供 (24) 数据流传送。

A．面向连接的、不可靠的
B．无连接的、不可靠的
C．面向连接的、可靠的
D．无连接的、可靠的