1. Service providers have internal channels to solve commercial advertising problems. If the service provider can't operate internally, the explanation is false. If it can use internal relations to contact auditors directly, it means that it is trustworthy and can communicate further.

2. With the increase of the number of service providers, the market becomes more and more chaotic. When choosing a service provider, people should pay attention to factors such as scale, word of mouth, word of mouth and popularity. Only service providers who can give satisfactory answers in these aspects are worthy of cooperation.