draw on butter or carve ice—a futile undertaking;work fruitlessly; work hard but to no avail
❍ 你难道不觉得自己在～吗？有什么用呢？ Don’t you think that you’re drawing on butter or carving ice? What’s the use of it?
画脂镂冰hua zhi lou bing
draw on butter or carve ice—futile undertaking
画脂镂冰huà zhī lòu bīnɡ
镂：雕刻。在油脂上画画，在冰上雕刻。比喻做无用功，白费力气。a futile undertaking, work hard but avail, work fruitlessly