grooving of valve seat

例句：

1. 1.The car was beautifully polished before the party.
   在派对前，这辆车被精心打磨得非常漂亮。
2. 2. She grooving her hair with a comb.
   她用梳子梳理头发。
3. 3. The floor was grooving after the rain.
   雨后地面变得光滑。