![](https://lstatic.shangxueba.com/sxbzda/h5/images/m_q_title.png)
What does the man say is a drawback to the process of restoring books?A.It's very expensiv
What does the man say is a drawback to the process of restoring books?
A.It's very expensive.
B.It hasn't proven to be totally effective.
C.It can be damaging to some books.
D.It can't be used on books published before 1850.
![](https://lstatic.shangxueba.com/sxbzda/h5/images/tips_org.png)