Typically, an unsolicited phone call from management inquiring if the service in their room is up-to-standard, and offering to send a manager to supervise the next cleaning, improves their behavior.

一般来说，想要让这些客人行为检点一些，可以让客房总管主动打一个电话过去，询问客户服务是否达标，并派一个经理过去监督清理工作。

youdao

Unsolicited means "not asked for." so cold calling is the skill of making a sales call to someone who is not expecting you.

unsolicited的意思是“不是别人主动要求的”，所以打“无约电话”也就是给那些不期望接你电话的人打销售电话。

youdao

Six weeks ago Microsoft executives made an unsolicited call to Mr. Bates and Silver Lake's Mr. Durban, said people familiar with the matter.

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People get annoyed when someone calls randomly on a landline, and get outright outraged when an unsolicited call comes in to their cell phone.

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The scam starts with the victim, often an older person, receiving an unsolicited call from someone claiming to be from their bank and suggesting their card needs replacing.

BBC: Man on telephone