their的形容詞性物主代詞和名詞性物主代詞

　　例句：

　　I joined my wail to theirs, loud and bitter.

　　我和他們一起慟哭，哭聲又高又痛苦。

　　Japan's higher education is superior to theirs.

　　日本的高等教育比他們的好。

　　Both England and the US said the island was theirs.

　　英國和美國都說這個島是他們的。