flapper coil

例句：

1. 1. The engineer designed a special coil to improve the performance of the motor.
   工程师设计了一个特殊的线圈来提高电机的性能。
2. 2. The coil was made from a special material that could withstand high temperatures.
   这个线圈是由一种特殊材料制成的，可以承受高温。
3. 3. The coil was used in the construction of the new bridge, providing a stable and reliable connection.
   这个线圈被用于新桥的建设中，提供了稳定可靠的连接。