●Communication protocols are (66) connection－oriented or connectionless, (67) wh

●Communication protocols are (66) connection-oriented or connectionless， (67) whether the sender of a message needs to contact and maintain a dialog with the recipient or (68) send a message without any prior connect and with the hope that the recipient receives everything (69) .These methods

(70) the two ways that communication is implemented on networks.

(66) A．not

B．neither

C．either

D．all

(67) A．fulled

B．flooded

C．depending on

D．defined by

(68) A．immediately

B．simply

C．accordingly

D．properly

(69) A．in order

B．in array

C．in series

D．in queueing

(70) A．make known

B．disclose

C．reveal

D．discover

C,C,B,A,C