gravity observation
| method
| gravity observation | |
| tech. | 重力观测 |
| method | |
| gen. | 法; 标准; 水平 |
| environ. | 方法 |
| hydroel.st. од. | 方法 |
| mech. | 电火花法 |
| |||
| 重力观测 | |||
|
gravity observation : 4 phrases in 2 subjects |
| Surveying | 1 |
| Technology | 3 |