chrome free and formaldehyde free tannage

lead free and cadmium free

deep-water channel in the north channel

disease of one channel involving another channel

Free rider psychology

(Pb)lead-free

．OH free radical

·OH free radical

100m free style

1150mm free standing last-stage steel blades

1-Diphenyl-2-picrylhydrazyl DPPH free radical

2-D free shear turbulent flows

2-torsion-free

3-D free curved surface

3-D free shear layer

3D free surface

3-free

6-tetramethyl-1-piperidinyloxy free radical

a free floating sensing diaphragm