形态学

The artist was so engrossed in his painting that he didn't notice the people watching him.

这位艺术家是如此着迷于画画，都没有注意到大家在注视着他。

Hair follicle is an important and complex epidermal appendage of skin, composed of hair shaft, inner root sheath and outer root sheath.

毛囊是皮肤重要而复杂的附属结构，从内向外依次由毛干、内根鞘和外根鞘组成。