tuned feeder

例句：

1. 1. The engineer used a tuner to adjust the pitch of the guitar.
   工程师使用一个调音器来调整吉他的音调。
2. 2.The musician tuned his instrument before performing.
   音乐家在表演前调整了他的乐器。
3. 3. The car's engine needs tuning to improve its performance.
   汽车发动机需要调音以提高性能。