to be on guard
时刻戒备着
on guard at all times
戒备森严
tight security
对他应有所戒备
be on one's guard towards him
处于戒备状态
in a state of alert
汉译英翻译词典收录86165条汉英翻译词条，基本涵盖了全部常用中文字词的英语拼写、翻译、音标、读音、用法、例句等，是英语学习的有利工具。