（1: if rust is caused by adhesion of other metals, cloth and neutral detergent can be used to scrub the rusty place, then clean it with clean water, and then dry it with dry cloth. Pay attention not to leave neutral detergent on it.
（2: in the case of air pollution near busy streets, rust prevention treatment must be carried out regularly, and soapy water shall be used for cleaning in light circumstances.
（3: when cleaning, the cleaner may touch the garbage can with his hand, so that the hand lines or dirt on his hand will cause rust. At this time, we can pour a little alcohol and acetone on the rag for cleaning, then use cleaning solution to clean, then use clear water to wash the solution, and use a clean rag to dry.