| |||
| 可变密度调制录音; 疏密录声 | |||
| |||
| 变密度记录 | |||
|
variable-density recording : 5 phrases in 3 subjects |
| Oil / petroleum | 1 |
| Technology | 3 |
| Television | 1 |
| |||
| 可变密度调制录音; 疏密录声 | |||
| |||
| 变密度记录 | |||
|
variable-density recording : 5 phrases in 3 subjects |
| Oil / petroleum | 1 |
| Technology | 3 |
| Television | 1 |