英语谜语 Write the name of a water bird thant rhymes with Don

Donald Duck 唐老鸭

ain't 是be not的缩写
例如
I ain't = I am not
you ain't = you are not
he ain't = he is not
其它情况类同 根据主语决定是be的哪个形式

ain't
KK: []
DJ: []
【口】=am not, are not, is not, have not, has not

ain't 是am not的缩写，水鸟名的确想不出来，只查到天鹅是swɔn