flat counter-sunk head screw

例句：

1. 1. The car was fixedwith a flat counter-sunk headscrew.
   这辆车是用一个平底沉头螺丝固定住的。
2. 2. The engineer used aflat counter-sunk head screw tohold the machine together.
   工程师用一个平底沉头螺丝把机器连接起来。
3. 3.The construction worker tightened the flat counter-sunk head screw on the wall.
   建筑工人在墙上拧紧了一个平底沉头螺丝。