adj.注意的；警惕的；不眠的；醒的
You must be watchful of your health. 你必須注意你的健康。
They were not very watchful of the traffic lights. 他們并不很注意紅綠燈。
We should be watchful of computer viruses. 我們應(yīng)該警惕計(jì)算機(jī)病毒。
n.警覺性；慎重
