?丧失警惕
... come off guard 【军】离防; 下防 lower one's guard 丧失警惕 drop one's guard 丧失警惕 ...
?轻视而漫不经心
[treat sth.lightly;let down one's guard;adopt a casual attitude;lower one's guard] 轻视而漫不经心 [stealthily substitute one thing for another] 暗中以假换真或以次换好 ..
掉以轻心
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。