ductless的音标：ductless的英式发音音标为：['dʌktlɪs]ductless的美式发音音标为：['dʌktlɪs]...

Endocrinology is defined as the study of the ductless or endocrine glands and their internal secretions.内分泌学的定义是:研究无管腺或称内分泌腺及它们的内分泌的科学....

adj.无管的...