戒备的

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

"警处于备状态,随时准备应付任何可能发生的骚乱。"

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

敌军显示出进攻的迹象，部队不得不进入备状态。

The dog jealously guarded its bone.

那狗备地看管着它的骨头。