Đáp án đúng:
Phương pháp giải:
Giải chi tiết:Ta thấy một mắt xích nhựa ABS có \(\begin{array}{*{20}{c}} {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,CN\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{C_6}{H_5}} \\ { - C{H_2} - \mathop C\limits^| H - C{H_2} - \mathop C\limits_| H - C{H_2} - \mathop C\limits^| H - } \\ {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,CH = C{H_2}\,\,\,\,\,\,\,\,\,}\end{array}\)