1) Press the green button once and carefully note the spread of the wave. Now select "Slow Motion", press the restart button at
the top left of the screen, then click the green button again to see the wave again as it first spreads from left to right and from back again. What path does the reflected wave take?
White spots are often the result of heat and water on the surface. These white spots are also called White Mold. You can wash off this mold with a tablespoonofbaking soda, and a teaspoonof water.