| | | | | | | | | | | | | | | | ① | 30%~50% ② | 50%~70% ③ | 70% | | | | | | | | | A | | | 5 1 | 5 | 2 3 4 | | | | | | | | | | | | | | | | | | 1. DVD | 2. | | 3. | | | |