watchful

形容词 watchful:

1. carefully observant or attentive; on the lookout for possible danger
   同义词：argus-eyed, open-eyed, vigilant, wakeful
2. experiencing or accompanied by sleeplessness- Shakespeare
   同义词：insomniac, sleepless

1. A watchful nurse tending a critically ill patient.
   照顾一个重病号的谨慎的护士
2. Be sure to be watchful or alert.
   必须留神，千万要提防。
3. We should be watchful of computer viruses.
   我们应该警惕计算机病毒。
4. The guard should be watchful during the night.
   警卫在黑夜里也应该警醒。