牛津词典：
a common bird that lives on or near water and has short legs, webbed feet and a wide beak. There are many types of duck , some of which are kept for their meat or eggs.
鸭子的构成特征：
一种常见的鸟（a common bird）生活在或靠近水的地方（lives on or near water）有短腿（and has short legs）蹼足和宽喙（webbed feet and a wide beak）鸭子的属性特征：
鸭子有很多种类（There are many types of duck）一些鸭子被饲养为了它们的肉或者蛋（some of which are kept for their meat or eggs）单词选自：
人教精通版小学《英语》三年级上册