According to the personal library, in some Lego training institutions, the cleaning work of plastic building blocks is to clean the posts, that is, the building blocks used in class every day are soaked in water with neutral cleaning liquid or mild laundry detergent for 15 minutes, brushed with soft wool shoes, and then washed in a clear water basin for 2 13 times. After cleaning, wipe the water off the building blocks with absorbent cloth, and then put it on the desk.