step·ping stone
noun/ˈstepɪŋ stəʊn/
/ˈstepɪŋ stəʊn/
- one of a line of flat stones that you step on in order to cross a stream or river
（小溪、小河中的）踏脚石 - something that allows you to make progress or begin to achieve something
进身之阶；垫脚石；敲门砖 - a stepping stone to a more lucrative career
涉足更赚钱的行业的敲门砖
- a stepping stone to a more lucrative career