single-seat valve

例句：

1. 1. The new car has a single-seat valve and is easy to drive.
   这款新车只有一个座位，驾驶起来很方便。
2. 2.The old man was driving with a single-seat valve, which made him feel uncomfortable.
   那位老人开车时用的是单座阀，这让他感到不舒服。
3. 3.The engineer replaced the single-seat valve on the engine, which improved the performance of the car.
   工程师更换了发动机上的单座阀，从而提高了汽车的性能。