Simone
adj. 警觉的, 灵敏的n. 警戒, 警报vt. 警惕, 使意识到Troops are on the alert against any possible aggression. 军队戒备着可能的来犯。The alert leopard went up to a deer quietly. 警觉的豹子静悄悄衡物地走近一只咐凳液鹿。Although he's over eighty his mind is still remarkably alert. 他虽已年过八十, 但粗禅头脑仍然十分机敏。An alert listener will have noticed the error. 耳朵尖的人能听出这个错。
