theca

例句：

1. 1. The orchestra needed a new theta to replace the old one.
   乐队需要一个新的调音器来替换旧的。
2. 2.The conductor had to adjust the theta for better sound quality.
   指挥家不得不调整调音器以获得更好的音质。
3. 3.The theta was used to tune the instruments in the concert hall.
   调音器被用来在音乐厅中调校乐器。