have/keep (your) wits about (you)
to be ready to think quickly in a situation and react to things that you are not expecting.
Cycling is potentially very dangerous in London - you really need to keep your wits about you.
英语词组固定搭配大全包含18674条英汉双解词组，基本涵盖了全部常用英文词组、短语的翻译及用法，是英语学习的有利工具。