?一级导体
... 三层挤出机 triple extruder 一级导体 first class conductor 双辊式机架 double-hellogh stand ...
[物]?第一类导体
... fire point 燃点 first class conductor 第一类导体 first harmonic 第一谐波 ...
Once, I mistakenly found myself in First Class, where the conductor had a go at me.
BBC: News | UK | Commuting: A lottery for the visually impaired
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。