blackadj.黑的；不加牛奶的；很脏的；愤怒的；令人沮丧的；邪恶的；阴沉的；机密的；黑色幽默的n.黑色；黑人；黑色物v.抵制；(使)变黑blackheart黑心病,黑心材

1. Shortish, greenish bill and black legs indicate this species.
   嘴短偏绿色而脚黑色正是三趾鸥的特徵。