| | | | | | | | | | | | | | | | 2024 3 27 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GB/T4754 ︱ | 2017 | 2018 | | | 3 | 2 | | | | | | | | | | | | | | | 20% | | | | | | | 80％ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 15% 10% 5% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ︹2021︺ 31 | | ︹2020︺ 75 | | | | | | | | | | | | | | | | | | | | | | 3 | 1 | | | | | | | | | | | | | | | | | |