MARK THE LETTER A, B, C, OR D ON YOUR ANSWER SHEET TO SHOW THE UNDERL...

Câu 23: Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction. (A) The policeman warned the tourists (B) not walking alone (C) in empty streets (D) at night. A. The B. not walking C. in D. at night