keep (your)/an eye on (something/someone)
to watch or look after something or someone.
Could you keep an eye on the baby for me a while?
I kept my eye on him all the time as I felt sure he was about to do something stupid.
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。