Vitaphone, as this system was now called, was publicly introduced on August 6, 1926, with the premiere of Don Juan; the first feature-length movie to employ a synchronized sound system of any type throughout, its soundtrack contained a musical score and added sound effects, but no recorded dialogue—in other words, it had been staged and shot as a silent film.
Cats, dogs, and many nocturnal creatures appear to have glowing eyes because the back of their eyeballs include a special reflective layer called the tapetum lucidum. This helps animals (cats in this case) see better in low light by working like a mirror on the retina to reflect the light back through the eyes.
The heart has four chambers: two atria and two ventricles. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle. The right ventricle pumps the oxygen-poor blood to the lungs. The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle.