风扇的来回摆动让整个房间都凉快起来。

The fan's gentle ___oscillation cools the entire room.

在危机期间，他在希望与绝望之间的摇摆显而易见。

His ___oscillation between hope and despair was evident during the crisis.

电路中的高频振荡需要被控制以确保设备稳定运行。

High-frequency ___oscillation in the circuit needs to be controlled for stable device operation.