Sir Isaac Newton, held the theory that light<span> was </span>made<span> up of tiny particles. In 1678, </span>Dutch<span> physicist, </span>Christiaan Huygens<span>, believed that </span>light<span> was </span>made<span> up of waves vibrating up and down perpendicular to the direction of the </span>light<span> travels, and therefore formulated a way of visualizing wave propagation.</span>
2. In 1945 a U.S. Air Force bomber accidentally crashed into the Empire State Building, killing fourteen people and damaging the 78th and 79th floors.
4. No infinitives are used. Sentence 4 contains a gerund.
5. includes Steve writing about himself in the first person.
That what i got and if any incorrect then sorry I try my best.