◎ 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