| 1 | The pre-Qin days were China's bronze age. | |
| 2 | After the Bronze Age and the Iron Age. | |
| 3 | In terms of technical development, people were going form the Stone Age to the Bronze Age. | |
| 4 | After the Bronze Age and the Iron Age, then came the Gold Era. | |
| 5 | In terms of technical development, people were going from the Stone Age to the Bronze Age. |