1. Birds having keeled breastbones for attachment of flight muscles.
胸部有脊状突起并附着有用于飞行的肌肉的鸟。
1. \u0039\u0031\u0031\u67E5\u8BE2\u00B7\u82F1\u8BED\u5355\u8BCD
1. The doctors separated the twin's livers, repositioned their hearts and rebuilt their breastbones.