To _(1)_ a TCP connection , that activating atation sends a message to another station.that station responds to the activating station that it is ready to establish a communication session.the first station then responds to confirm the connections and an _(2)_ transfer of data _(3)_ to establish data transfer controls.Connection-oriented sessions are useful for _(4)_ data exchanges or when a _(5)_ permanent connection is necessary.

(1)

A.creat

B.set up

C.produce

D.build

(2)

A.initial

B.empty

C.useful

D. active

(3)

A.tries

B.begins

C.take place

D.prepares

(4)

A.short

B.prolonged

C. user

D.control

(5)

A.very

B. prepably

C. apparently

D.relatively

答案：BACBD

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