joint on square

例句：

1. 1. The joint between thetwo pieces of wood is loose.
   两块木头之间的接合处松动了。
2. 2. He hadto join the team by working on weekends.
   他不得不在周末工作来加入团队。
3. 3. The car's engine has abad joint that needs to be replaced.
   这辆车的引擎有一个坏的接头需要更换。