铅笔画不出界限橡皮擦不掉距离
[qiān bĭ huà bù chū jiè xiàn xiàng pí cā bù diào jù lí]
A pencil cannot draw boundaries, and an eraser cannot erase distance. This illustrates that even though certain limitations (boundaries) may seem trivial (pencil drawings), there's a gap or difference (distances) between things or people that can't be easily erased (erased).