He bought a book that could give him much knowledge and ____could help him to kill the the time是that 还是which 我们一中英语老师说是that 只有which is the book ___ you bought to me才不能有 which这个不存在重复的问题 and连

He bought a book that could give him much knowledge and ____could help him to kill the the time是that 还是which 我们一中英语老师说是that 只有which is the book ___ you bought to me才不能有 which这个不存在重复的问题 and连
He bought a book that could give him much knowledge and ____could help him to kill the the time
是that 还是which
我们一中英语老师说是that
只有which is the book ___ you bought to me才不能有 which
这个不存在重复的问题
and连接的两个从句先行词是一样的
求教

He bought a book that could give him much knowledge and ____could help him to kill the the time是that 还是which 我们一中英语老师说是that 只有which is the book ___ you bought to me才不能有 which这个不存在重复的问题 and连
两者都行!
从本质上看,从句的主语是a book,所以关系代词which和that都行.
我是震中的,我们也做到过类似一道题,答案是which,老师说that也是可以的,如果从和前面一致的角度来看that更好.