【题目】In our class, there's a ________ that when it is somebody' s birthday, they bring in a cake for us all to share.
A.conversation
B.tradition
C.discussion

【答案】B
【解析】句意：在我们班有一个传统：当有人过生日时他们带来蛋糕全班共享。A. conversation交谈，会话；B. tradition传统；C. discussion讨论。根据句意选B。