As long as a phone does not go "on-hook," activation of various line pushbuttons will automatically place the first line on hold without the use of a special "hold" button.

当电话机没有“接通”时，各种线路按钮激活自动将第一根线路置于保留状态，不需要使用特殊的“保留”按键。

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He was dying on the phone when he heard another mute button switch off and the voice of an even more senior executive came on the line.

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