IT WAS ________ A DIFFICULT QUESTION THAT WE COULDN’T ANSWER IT. A...

31. - 20 DE THI HOC KY II 20 DE THI HOC KY II
20 DE THI HOC KY II 20 DE THI HOC KY II
31. It was ________ a difficult question that we couldn’t answer it. A. so B. such C. very D. too V. There is a mistake in four underline parts of each sentences. Find the mistake.