concave grating

例句：

1. 1. Thecar's dashboard has aconcave grating for the radio.
   汽车的仪表盘有一个凹面格栅用于收音机。
2. 2.The old house had a concavegrating in its roof.
   旧房子的屋顶有一个凹面格栅。
3. 3. The engineerdesigned a concavegrating to improve airflowthrough the tunnel.
   工程师设计了一个凹面格栅来改善隧道内的气流。