gap at joint

例句：

1. 1. The car's engine has a big gap at the joint where the pistons meet.
   汽车发动机的活塞接触处有一个大的缝隙。
2. 2. The bridge was built to avoid a gap at the joint between the two cities.
   这座桥建造是为了避免两个城市之间的接合处出现缝隙。
3. 3. The old tree had a gaping hole in its trunk that needed to be filled.
   这棵老树的树干上有一个需要修补的大洞。