-- What’s your favorite sport ?

-- _________. It’s interesting.

A．Math

B．T-shirt

C．E-mail

D．Basketball

The X.25 standard specifies three layers of functionality. Which layers of the OSI model correspond to the X.25 layers

A．the Physical, Network, and Session Layers

B．the Physical, Data Link, and Network Layers

C．the Physical, Data Link, and Transport Layers

D．the Physical, Session, and Presentation layers