1. 18 | | | | 2. 15 | 8% | | 3. 24 | | | 4% | 4. 0.05% | 3% 2.8% | | 5. 20ppm~25ppm | | | 6. | 28 12 16 | | 10% | | 7. | | | 12 1 1 | 7 8 | 3% | | | | |