Hurriedly, they packed their belonging and set off ______the direction of the river．

A．for

B．to

C．at

D．in

按覆盖的地理范围进行分类，计算机网络可以分为三类 ______。

A．局域网、广域网与25网

B．局域网、广域网与宽带网

C．局域网、广域网与ATM网

D．局域网、广域网与城域网