--where are your grandpanrents from ?They ____(write)their story in the study

问题有矛盾啊
问的是你的祖父母来自哪里（即哪里人）
回答的是在书房里写故事。
晕！
而且grandparents,不是grandpanrents多了个n.
将问句改一下就对啦：
Where are your grandparents ?They __are writing__(write)their story in the study

have written