With water soluble pen draw ramps in Georgia. Each color represents a water-soluble pen line color, the first of several paintings.
用水溶笔在格上画斜道。每种水溶笔的颜色代表一种线的颜色,先画几种。
2
Imagine a way in which you could use the same pen to draw a black line on a white surface and a white line on a black surface without knowing what colorthe surface is.