Explain how airplane wings and the wings of birds affect the air flowing over them to produce lift

Which accurately compares concave and convex lenses?

An element becomes a positively charged ion when itloses protons.loses electrons.gains electrons.gains neutrons.

Select the best definition for wavelength. the height of an oscillating electromagnetic wave the rate at which electromagnetic waves oscillate. the distance between two crests of an electromagnetic wave. the oscillations of electric and magnetic fields select the best definition for frequency. the oscillations of electric and magnetic fields. the height of an oscillating electromagnetic wave. the distance between two crests of an electromagnetic wave. the rate at which electromagnetic waves oscillate