Because there's nothing before the x, it automatically becomes a 1.
If it's a whole number, you know that the denominator is a 1, so when you plot the graph with the slope of 1, you always go up 1 and over to the right one.
Answer: Electrons in water act in a similar way to visible light so they don't absorb or reflect most of the light. Instead they allow it to pass through relatively unimpeded, absorbing wavelengths like infrared and reflecting invisible UV
