Why does the Baotou City Direct Drinking Water Card disappear after charging but not using it?

It’s getting cold. Remember to cover yourself with a quilt at night. You don’t have to dress beautifully. But it must be warm. Remember to adjust the temperature of the water before taking a shower. Stop eating too much cold fruit. If you have a cold, you must go to the hospital to take medicine. When you get up in the morning, don't throw off the quilt. It's easy to catch a cold that way. After washing your hair, be sure to wait until it is dry before going out. Eat well. Don't lose weight. No instant noodles allowed. Don't stay up late often. Take breaks on time. Call or text me when you are unhappy. Don't eat too spicy food. Don't drink carbonated drinks and don't drink cold water. Not good for your stomach. Look both ways when crossing the road. Take good care of yourself and don't get sick. Do you know? When you stay in bed at night, remember to turn down the LCD light of your mobile phone, and remember not to hold your mobile phone too close to your face. Mobile phone radiation is quite large! Take good care of yourself for me, health is the most important thing! Be sure to remember!