Which type(s) of electromagnetic radiation emitted by the Sun are absorbed byEarth’s atmosphere and do not reach Earth’s surface?A. long-wave radio waves, X-rays, and gamma raysB. short-wave radio waves and gamma raysC. infrared light, X-rays, and gamma raysD. X-rays20. A student is wearing a pair of sunglasses designed to reduce the glare fromreflected surfaces. When the student tilts her head to the side and back again, shenotices that the brightness of the blue sky changes in intensity.The student wonders why the intensity is affected by the orientation of hersunglasses. The light coming from the sky toward her sunglasses has most likelyundergoneA. absorptionB. diffractionC. polarizationD. refraction21. During an investigation, a student aimed a beam of light through a round openingin an opaque barrier. The light passing through the opening travelled to a screen ashort distance away. When the student repeated the procedure with the beam goingthrough a smaller opening, he found that the circular projection of light on thescreen became larger with less distinct edges.What is responsible for the change in characteristics of the circular projection?A. diffraction of lightB. reflection of lightC. refraction of lightD. polarization of light