control volume

例句：

1. 1. The engineer controls the volume of the sound system.
   工程师控制声音系统的声音大小。
2. 2. The manager adjusted the volume to ensure everyone could hear clearly.
   经理调整了音量以确保每个人都能清楚地听到。
3. 3. The singer controlled her volume to match the background music.
   歌手控制了她的音量以匹配背景音乐。