oval hexagon head bolt

例句：

1. 1.The engineer used a special oval hexagon head bolt to fix the door.
   工程师使用一种特殊的椭圆形六角头螺栓来固定门。
2. 2.He tightened the oval hexagon head bolts on the wall with a wrench.
   他用扳手紧固了墙上的椭圆形六角头螺栓。
3. 3.The construction workers were busy installing oval hexagon head bolts in the ceiling.
   建筑工人正在忙着在天花板上安装椭圆形六角头螺栓。