上 覆 层 : 54 phrases in 12 subjects |
Automobiles | 1 |
Aviation | 1 |
Bridge construction | 1 |
Desert science | 2 |
Drilling | 6 |
Electronics | 1 |
Engineering geology | 6 |
Explosives and Explosive Ordnance Disposal | 8 |
Geology | 2 |
Geophysics | 1 |
Oil / petroleum | 10 |
Technology | 15 |