第一节（共5小题；每小题1分，满分5分）
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。
1．Why does the woman have to wait ?
A．Because all the lines are busy .
B．Because the person she wants to speak is not in.
C．Because the operator is very busy.
