watchful /ˈwɒtʃfʊl/ star1

• 1.  

  ADJ（形容词） Someone who is watchful notices everything that is happening. 警觉的

  例：

  The best thing is to be watchful and see the family doctor for any change in your normal health.

  最好的做法就是保持警惕，身体一有变化就去看家庭医生。