taking a series of rhythmical steps (and movements) in time to music

forces acting on airfoils in motion relative to the air (or other gaseous fluids)

forces acting on airfoils in motion relative to the air (or other gaseous fluids)

feelings of envy and resentment of one social or economic class for toward another

feelings of envy and resentment of one social or economic class for toward another

not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)

not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)

not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)

not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)

not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)