【单选题】

Questions 47-49 refer to the following notice

We are proud to let you know that at our library, every (47) library card we give out is to a kid, and forty percent of all books that are checked out are for the children. So it is needless to say that kids prefer to use our facility as we can meet kids’ specific demands more than any other library.
We greatly acknowledge the importance of providing support for kids to read all through this summer. Statistics (48) that children who read a wide variety of books in summer have less difficulty in their reading skills at the start of school year. Reading is still (49) to as the strangest sign of success in the academic achievement.
A．referred
B．explained
C．suggested
D．required