Mary found it hard to concentrate on her work because the noise33/64Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions Mary found it hard to concentrate on her work because the noise because the noise it hard work to concentrateGiải thíchĐáp án : A Because + mệnh đề. Because of + N/Ving. Sửa A -> because of the noise