square nail

例句：

1. 1. He used asquare nail to hang up his coat.
   他用一个方形钉子挂起他的外套。
2. 2. Thecarpenter used square nails to reinforcethe wooden beams.
   木匠用方形钉子加固木梁。
3. 3. The builders used squarenails to secure the wooden planks together.
   建筑工人用方形钉子将木板固定在一起。