听对话，回答以下各小题。
【小题1】Why does the boy say sorry to the girl?

A．Because he lost the book.

B．Because he lent the book to his grandma.

C．Because he can’t return the book now.

【小题2】When will the boy return the book to Mary?

A．He needn’t return it.

B．He will return it this Sunday.

C．He will return it next Monday.