接缝规

例句：

1. 1. The car's engine is a joint of metal.
   汽车的引擎是一个金属接头。
2. 2. They used to join hands and dance together.
   他们曾经手拉手跳舞。
3. 3. The two countries are at a joint in their relations.
   这两个国家在关系上存在分歧。