The reason why he was chosen remains unknown why在从句中是做宾语吗

The reason why he was chosen remains unknown why在从句中是做宾语吗 The reason why he was chosen remains unknown 这是同位语从句还是定语从句 关于同位语从句的问题eg.The reason why he was chosen remains unknown.这句 the reason why he was late for school is still unknown to us The reason why he did it was not clear.这句话why引导的是什么从句 The reason why ...是什么从句? 定于从句还是同位语从句?the reason why he missed the train was that he g The reason why he was late was true . He continued_____(explain) the reason why he was late 前半部分是定语从句还是同位语从句?The reason why he was dismissed is that hew The reason why he didn,t come was（ The reason why his being late is he was badly ill错在哪?