某气象局预报称：“明天本市的降水概率为70%”．这句话指的是（　　）

A．明天本市一定下雨

B．明天本市下雨的可能性是70%

C．明天本市70%的时间下雨，30%的时间不下雨

D．明天本市70%的地方下雨，30%的地方不下雨

In the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet.
A socket is basically an end point of a communication link between two applications. Sockets that extend over a network connect two or more applications running on (31) computers attached to the net-work. A socket (32) two addresses: (33) . Sockets provide a (34) communication channel between one or more systems. There are (35) sockets separately using TCP and UDP.

A．unique

B．separate

C．same

D．dependent