Questions 17-20 are based on the following monologue.
Which country is not mentioned as in the area of "hunter belt"

A．To train the international graduates to be T-A’s.
B．To make sure students can understand the Foreign T-A’s.
C．To help their students improve their spoken English.
D．To offer to those who failed to take it outside the U.S.

A．They are kept on the shelves in another room.
B．They can be checked out from the library.
C．They can only be read a few hours in the library.
D．They can be accessed to with no aid of the librarian.