Fang's wastewater is extracted with silver, with national patents and mature technology. Students do not need experience. At the same time, long-distance correspondence is carried out to protect the society and the training cost is low. And the company has been buying silver at the market price for many years. We solemnly promise that the purity of silver can be taken to the jewelry processing shop for quality appraisal. If the technology is distorted, we will lose double indemnity!