Mark the letter A, B, C or D that needs correction: The (A) shopkeeper warned5/15Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction. The (A) shopkeeper warned the boys don't (B) learn their (C) bicycles against (D) his windows.Thedon'ttheiragainstGiải thíchĐáp án B.