rotary air pump

例句：

1. 1. The rotary valve is used to control the flow of gases.
   旋转阀用于控制气体的流量。
2. 2.The rotary saw is a versatile tool for cutting wood.
   旋转锯是切割木材的多功能工具。
3. 3. The rotary drill uses a motor to rotate the bit and drill into the material.
   旋转钻机使用电动机来旋转钻头并钻入材料。