第一节
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
When will Bill come back

A． A musical-comedy troupe
B． A ballet company.
C． An orchestra.

A．how Cultural Survival, Inc. helped a tribe to solve the problem of copper mining
B．why local cultures should be saved
C．the work of Cultural Survival, Inc
D．the difficulties in saving local cultures