喻指为某项事业的成功而创造有利条件的人或组织person or organization that creates conditions favourable to the success of an undertaking ; cobblestone

• 我主要是要做好“人梯”，当好“铺路石”。

  I primarily want to be a "human ladder", sacrificing myself for the good of the project, and also a "cobblestone", able to help create the conditions for success.

• 我愿做一块煤，燃烧自己，发出光和热，燃成灰烬，还要用做铺路石。

  I am willing to be a piece of coal, to burn myself and give out light and heat, burning into ashes, and I also want to be a "cobblestone"