警戒,机敏
Alertness \A*lert"ness\, n. The quality of being alert or on the alert; briskness; nimbleness; activity.
alertness n 1: the process of paying close and continuous attention [syn: {watchfulness}, {vigilance}] 2: a state of readiness to respond; "alerting was indicated by the desynchronization of the EEG" [syn: {alerting}] 3: lively attentiveness [syn: {on the qui vive}]