n. a precautionary measure warding off impending danger or damage or injury etc.
n. the trait of practicing caution in advance
n. 预防, 留心, 警戒
vt. 预先警告
1. Take a precaution by wearing a helmet when riding a bike.
骑自行车时戴上头盔是一种预防措施。
2. The doctor advised some precautions to avoid getting sick in winter.
医生建议了一些预防措施，以避免在冬天生病。
3. Always keep a first aid kit at home as a precaution.
在家中始终备有急救箱作为预防措施。