1.For Mona Lisa, he used a thin-grained piece of poplar tree and applied an undercoat of lead, white.

在创作《蒙娜丽莎》时，他使用了棵纹理很薄的白杨树，并涂了白色的铅底漆。

2.It consists of two layers of transparent hair, a soft thick undercoat and a layer of hollow guard hairs.

它有两透明皮，柔软厚实的皮，中空的护。

3.He then applied a series of undercoats, letting them dry before applying another.

然后，他涂了系列的底漆，等它们干了再涂。

4.But for many mammals, hair grows in two layers consisting of a shorter undercoat of ground hairs covered by longer guard hairs.

许多哺乳动物的发生长为两，由较短的作为底发，上面覆盖较长的保护。

5.The lead white undercoat reflects the light back through his glazes, giving the picture more depth, and in essence, lighting Mona Lisa from within.

铅白色的底漆将光线通过釉料反射回来，使这幅画更有深度，从内部照亮了《蒙娜丽莎》。

6.Woolly mammoth fur was composed of two coats: an inch-long yellowish brown undercoat that was covered by a coarse dark brown overcoat that could grow more than two feet long.

长猛犸象的皮有两：英寸长的黄褐色下皮，上面覆盖着粗糙的深棕色外，可以长到两英尺多长。