gear with curved teeth

例句：

1. 1.The gears on the car's engine are designed to work together seamlessly.
   汽车发动机上的齿轮设计得可以无缝协作。
2. 2.The gears in the transmission system are crucial for smooth operation.
   传动系统中的齿轮对于平稳运行至关重要。
3. 3. The gears on the bicycle are made of high-quality materials to ensure durability and performance.
   自行车上的齿轮由高质量的材料制成，以确保耐用性和性能。