Ten years ago, hundreds of Nigerian schoolgirls were abducted and spirited away by the militant group called Boko Haram. Some of the young women managed to escape. Nigerian soldiers rescued others. Today, more than 90 remain missing. Some have died; others are still being held. Journalist Adaobi Tricia Nwaubani tells The World’s Carolyn Beeler why some of those who were  kidnapped remain married to those who captured them.