她学会了自己给房子拉接电线、敷设水管。She learned to wire and plumb the house herself.他们曾保证水管一年前彻底检修过。They had ensured the plumbing was overhauled a year ago.总水管破裂了，整条街道发了大水。A water main burst and the street was flooded....
戒指内侧有一层厚厚的锈斑。The tarnish lay thick on the inside of the ring.请擦去刀上的锈斑.Please scour rust spots from the knife.这些锈斑可能是由于在海上受潮引起的.Maybe the rust stain is due to dampness at sea....