If you want to buy a water card in the laundry room, it is usually sold in the dormitory duty room. The restroom is at the east gate, which is the direction from Tian Jiabing College to Baochu Road. I remember it was once in 5 yuan, paid in cash. You can also buy water cards and wash them in dormitory buildings with public toilets, such as 7 buildings and 8 buildings. It depends on how much water you actually use. Generally, it can be washed for less than 3 yuan.