叩けば埃が出る
1
scratch the surface and you will find dirt;look close enough and you will find the flaws;hit something and dust comes out
Other forms
叩けばホコリが出る 【たたけばほこりがでる】 · 叩けば埃がでる 【たたけばほこりがでる】 (search-only kanji form) · 叩けばほこりがでる 【たたけばほこりがでる】 (search-only kanji form)