Question 6: Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs in each of the following questions: The correction (A) economy of this country is based (B) to a great extent (C) in its forests, which cover 80 (D) percent of its surface area.
Structure: – be + based + on: to be based on, to be based on
Eg: This film is based on a real-life incident. Hence: to => on
===============