I've called the maintenance worker.

我已经给维修人员打电话了。

Can you call the maintenance worker?

你能给维修工人打电话吗？

A coveralled maintenance worker ran into the lobby .

一个穿着工作服的保养工奔进门厅。

Instruct and training the maintenance worker on production line.

指导和培训生产线维修人员的工作；

The cause of this accident is the mistake on changing parts by maintenance worker.

发生事故的原因是设备维修人员错误更换零部件造成的。