坐标纸: 53 phrases in 21 subjects |
Agriculture | 2 |
Air defense | 2 |
Architecture | 1 |
Automobiles | 2 |
Bridge construction | 3 |
Business | 2 |
Construction | 3 |
Drilling | 2 |
Electronics | 2 |
Engineering geology | 1 |
General | 2 |
Labor law | 1 |
Mathematics | 2 |
Metallurgy | 1 |
Oil / petroleum | 4 |
Physics | 1 |
Scientific | 1 |
Space | 2 |
Technology | 17 |
Telecommunications | 1 |
Wind Energy | 1 |