(get) in on the ground floor
to become involved in something from its beginning.
Can someone tell me how you get in on the ground floor of a money-making deal like that?
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。