countersunk head

例句：

1. 1. The engineer designed a countersunk head for the machine to improve its efficiency.
   工程师为机器设计了一个倒置的头部，以提高其效率。
2. 2.The car's headlights were replaced with a countersunk head to enhance visibility at night.
   汽车的前灯被换成了倒置的头部，以增强夜间的可见性。
3. 3.The scientist used a countersunk head to study the behavior of microscopic organisms.
   科学家使用倒置的头部来研究微观生物的行为。