[jǐng tì]
be on guard against; watch out for; be vigilant; be on the alert
maintain sharp vigilance
保持高度警惕
exercise the highest vigilance
百倍警惕
relax vigilance
放松警惕
drop one's guard; be off one's guard
喪失警惕
heighten our vigilance and defend our motherland
提高警惕， 保衛(wèi)祖國
be vigilant against enemy sabotage
警惕敵人的破壞
Constant vigilance is necessary in order to avoid accidents.
為了避免意外事故， 必須經(jīng)常保持警惕。