万丈高楼从地起

wànzhàng gāolóu cóngdì qǐ

[the loftiest towers are built up from the ground; all things should be done gradually; great oaks from little acorns grow] 比喻凡事要从打基础做起

万丈高楼从地起, 你这些基础课没有学好, 以后就难以提高