moving from one place to another and back again

of concern to or concerning the affairs of other nations (other than your own)

of concern to or concerning the affairs of other nations (other than your own)

of concern to or concerning the affairs of other nations (other than your own)

of concern to or concerning the affairs of other nations (other than your own)

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)

an optical device for focussing a camera or other instrument automatically

an optical device for focussing a camera or other instrument automatically

an optical device for focussing a camera or other instrument automatically