Where repairs are required to inorganiczinc ethyl silicate primer without topcoats,for instance due to weldingdamage,the following procedure shall be applied:此句的Where repairs are required to inorganiczinc ethyl silicate primer without topcoats是什么结构?需要分析具第一句的具体的成分

Where repairs are required to inorganiczinc ethyl silicate primer without topcoats,for instance due to weldingdamage,the following procedure shall be applied:
此句的Where repairs are required to inorganiczinc ethyl silicate primer without topcoats是什么结构?
需要分析具第一句的具体的成分