vigilance
n. 警戒，警觉；失眠症
例句
She stressed the need for constant vigilance.
她强调必须时常保持警惕。
《牛津词典》
Constant vigilance is necessary in order to avoid accidents.
为了避免意外事故，必须经常保持警惕。
《新英汉大辞典》
It seems to me they still have some fight left in them. We shouldn't relax our vigilance.
他们余勇可贾，我们不能放松警惕。
