Normally a student would at least attend ______ classes each week.

A．A talkative person may not want the other to stop.
B．Some speakers may think the pauses others leave for them are too short.
C．A pause may be interpreted in different ways.
D．We should tolerate long pauses.

A．participate in the conversation
B．become involved in the conversation
C．disturb the conversation
D．interrupt the speaker by taking one's turn unexpectedly