 |
| |||
| 标度C声音测量仪器的标度，用来识别低频音波 | |||
| C scale: 10 phrases in 5 subjects |
| Earth sciences | 1 |
| Explosives and Explosive Ordnance Disposal | 2 |
| Metallurgy | 5 |
| Oil / petroleum | 1 |
| Oil processing plants | 1 |
|
| |||
| 标度C声音测量仪器的标度，用来识别低频音波 | |||
| C scale: 10 phrases in 5 subjects |
| Earth sciences | 1 |
| Explosives and Explosive Ordnance Disposal | 2 |
| Metallurgy | 5 |
| Oil / petroleum | 1 |
| Oil processing plants | 1 |