insurance certificate短语¹¹⁴⁴⁶⁷⁺⁴ 基本例句 保险证明书,保险凭证 It is well known that the economic evaluation report is the insurance certificate to the investor of petroleum E&P project as its complexities, uncertainties and high risk. 由于石油勘探开发的复杂性、不确定性和高风险性，经济评价报告被称作投资者的保险单。 cnki