THE LIBRARIAN IS ALWAYS ... HER DESK TO HELP THE READERS.A. ATB. O...

18. - 3500 CAU TRAC NGHIEM ON TAP AV THCS
3500 CAU TRAC NGHIEM ON TAP AV THCS

18. The librarian is always ... her desk to help the readers.

a. at

b. on

c. from

d. in

-> a