由于第三者插足，这对夫妻离婚了。

　　[误] The couple divorced because of the third person.

　　[正] The couple divorced because of a third party.

　　注：序数词一般常跟定冠词 the 连用，表示“第几”;而序数词和不定冠词 a 连用时表示的则是“另一个”。如： He won the third prize(他得了个三等奖)，He won a third prize(他第三次得奖)。