It was to companies' advantage to participate in the voluntary programme because it improved their corporate image; if they met the aforementioned criteria, the Ministry issued them a two-year certificate as a model company.
参加这种自愿方案对公司有利，因为这可以提升公司形象；如果它们达到了上述标准，该部就向其颁发为期两年的模范公司证书。