Feather picking in African greys may be linked to a deficiency of the amino acid arginine, and the presence of red feathers where gray ones would normally appear may be due to a deficiency of lysine.

缺乏氨基酸精氨酸可能导致拔毛，而红色羽毛的出现可能因为缺乏赖氨酸。

youdao

Standing at the window, I watched her walking briskly down the street, until the gray turban and white feather were but a speck in the sombre crowd.

我站在窗前，看着她轻快地在街上走着，直到她的灰帽子和白羽毛消失在人群当中。

youdao