A fine respiratory tube in the lungs of reptiles, birds, and mammals. It is formed by the subdivision of a bronchus and in reptiles and mammals it terminates in a number of alveoli.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。