Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
He has been very interested in doing research on ……………… since he was at high school.
Correct answer: A
After a preposition, a noun is needed.
The “-al” ending is the adjective’s ending, and the “-ly” ending is the adverb’s ending, so answer B and D are eliminated.
Answer A: biology (n): biology;
Answer C. biologist (n) biologist (the “ist” ending is the noun ending for people).
In terms of meaning, choose answer A.
He has been very interested in doing research in biology since he was in high school.