这种鸟类表现出明显的二态性，雄鸟有着鲜艳的羽毛而雌鸟则呈灰褐色。

This bird species shows ___dimorphic characteristics, with males having colorful plumage while females appear grayish-brown.

硫磺是二形的，可以结晶为斜方硫和单斜硫两种形态。

Sulfur is ___dimorphic, crystallizing as both rhombic and monoclinic forms.