Generally speaking, Lao Fengxiang is still very formal. If it is B or C, the invoice written on the signature is supported. Please look at the certificate issued by a more formal and better institution. If it doesn't say that it has been handled, it's not B. If there is a problem, you can go to a better testing institution for inspection. If you have any questions, you can find the inspection fee of the mall. Emerald is generally above 150, and such testing institutions can do it.

Goods B and C in regular shopping malls are still relatively few, because many of them now have certificates, or goods A can sell at higher prices, which consumers prefer.