Primary Reference
| Clock
| primary reference | |
| el. | 主要参考 |
| clock | |
| dart. | 钟面; 钟; 棋钟 |
| met. | 时计 |
| racing | 速度表 |
| space | 钟; 时钟脉冲 |
| sport. | 计时 |
| telecom. | 同步脉冲 |
| voll. | 掩护发球 |
| |||
| 主要参考 | |||
|
Primary Reference : 22 phrases in 10 subjects |
| Automobiles | 2 |
| Aviation | 3 |
| Chemistry | 4 |
| Communications | 2 |
| Electronics | 4 |
| General | 2 |
| Information technology | 1 |
| Oil / petroleum | 1 |
| Oil processing plants | 1 |
| Telecommunications | 2 |