地道美语听力练习:集中供暖系统的锅炉发生故障

例句:High electricity bills point to a poor heating system or bad insulation.
高额电费开支说明供暖系统不足或建筑隔热材料不良。

2.service call 维修电话

例句:For example, a company could detect dissatisfied customers that explicitly reference a competitor in a service call.
例如，公司可以在服务呼叫记录中发现客户提到了竞争对手，从而发现可能会流失的客户。

3.come out 出现

例句:The truth is beginning to come out about what happened.
真相开始逐渐浮出水面。

4.come by 过来

例句:When Mary didn't come by nine o'clock, we gave her up.
玛丽九点还未到，我们认为她不会来了。