这两个句子都是 错句
第一句 多主语
应该是 What is planted by him?what是主语 这是被动语态
或 What does he plant what是宾语 这是主动语态
第二句 pass away 是终止系动词 不能 与 how long 连用
应该是 How long has his wife been dead?
或When did his wife pass away?