戒备的

Warnings of an enemy attack forced the troops onto the defensive.

敌军显示出进攻的迹象，部队得进入戒备状态。

The patrol police on duty are on the alert against any possible disturbances.

"值班巡警处于戒备状态,随时准备应付任何可能发的骚乱。"

The dog jealously guarded its bone.

那狗戒备地看管着它的骨头。