a system for screening luggage in airports; an agent passes a swab around or inside luggage and then runs the swab through a machine that can detect trace amounts of explosives
同义词：explosive trace detection??/??ETD
And she is reading the - an alphabet that was especially arranged so that the first letter she says - it doesn't go A, B, C, D, E.
NPR: A Beautiful Movie: 'The Diving Bell and the Butterfly'
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。