Only if you have this health certificate and this qualification can you be a rider, and it is not so easy for you to be a US group rider. After layers of screening, if you don't take the initiative to deliver meals and smoke and chat every day, you won't make money. Therefore, only when you are in good health can you get a health certificate, and then you can become a US delegation through your own efforts. The monthly income is still considerable, but you need to bear hardships.