tuning stub

例句：

1. 1. The engineer needs to tune the car's engine for optimal performance.
   工程师需要为汽车发动机调校，以获得最佳性能。
2. 2. The tuning rod is used to adjust the pitch of the guitar strings.
   调校杆用于调整吉他弦的音高。
3. 3. The tuning rod was damaged during the accident and had to be replaced.
   在事故中，调校杆受损，不得不更换。