 |
| |||
| ★ 调制系统 | |||
|
modulating system : 8 phrases in 4 subjects |
| Electricity | 4 |
| Hydroelectric power stations | 1 |
| Scientific | 2 |
| Technology | 1 |
|
| |||
| ★ 调制系统 | |||
|
modulating system : 8 phrases in 4 subjects |
| Electricity | 4 |
| Hydroelectric power stations | 1 |
| Scientific | 2 |
| Technology | 1 |