Mark the letter A, B, C, or D that needs correction: They are known3/15Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction. They are known (A) that colds can be avoided by (B) eating the right (C) kind of food and taking exercise regularly (D).They are knownbe avoided byrightregularlyGiải thíchĐáp án A.