General catalogues and special leaflets are being airmailed under separate cover.我公司的目录和商品转页另以航邮寄上.Quotation and sample books will be airmailed to you upon receipt of your specific inquiry.一受到贵方具体询价单,我方马上航空邮寄样品册并报价.The I...
然后通过大量实验筛选出两种有效添加剂环丁砜和六次甲基四胺.Following that, two effective additives - syclotersuphone and methenamine are found by series experiments.我们来讨论六亚甲基四胺.We examine the study of hexamethylenetetramine.以氨水、氯乙酸为原料,以六亚甲基四胺为相转移催化剂,...