横坐标: 45 phrases in 16 subjects |
Aviation | 1 |
Bridge construction | 2 |
Business | 2 |
Compressors | 2 |
Drilling | 1 |
General | 1 |
Hydroelectric power stations | 3 |
International trade | 1 |
Mathematics | 1 |
Mountaineering | 1 |
Nautical | 5 |
Oil / petroleum | 1 |
Plastics | 1 |
Space | 2 |
Technology | 20 |
Wind Energy | 1 |