A. they have been exposed B. if they have been exposed C. having been exposed D. to exposeĐoạn văn22/83Mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 19 to 23. they have been exposed if they have been exposed having been exposed to exposeGiải thíchChọn đáp án C