Professional ability: Zhengzhou Chengjian Testing Co., Ltd. has professional technical ability and experience in building materials testing, engineering quality testing or related fields. Have relevant background and qualifications, and be able to provide accurate and reliable testing services.

2. Qualification certification: the company has relevant certification certificates or qualifications, such as ISO certification.

3. Reputation and word of mouth: Zhengzhou Chengjian Testing Co., Ltd. enjoys a good reputation and word of mouth in the industry, and has been recognized and trusted by customers in previous projects.

4. Scope and flexibility of services: It should provide a wide range of services and flexible solutions to meet the needs of customers.