A modified muscular pouch immediately behind the stomach in the alimentary canal of birds, having a thick lining and often containing ingested grit, which aids in the mechanical breakdown of seeds before digestion.是什么意思_A modified muscular pouch immediately behind the stomach in the alimentary canal of birds, having a thick lining and often containing ingested grit, which aids in the mechanical breakdown of seeds before digestion.在线翻译_英语_读音_用法_例句