Read the passage and answer the question that follows. When the air is clear, the sunset will appear yellow, because the light from the sun has passed a long distance through the air and the blue light has been scattered away. If the air is polluted with small particles, natural or otherwise, the sunset will be more red. Sunsets over the sea may also be orange, due to salt particles in the air. The sky around the sun is seen reddened, as well as the light coming directly from the sun. This is because all light is scattered relatively well through small angles, but blue light is then more likely to be scattered twice over the greater distances, leaving the yellow, red, and orange colors.

1. As it is pointed out in the passage, the color of the sunset

(A) may be lighter than expected due to salt particles in the air   

(B) is red if the sky is clear           

(C) owes its blueness to the distance between the sun and the earth       

(D) depends on the weather conditions and the location where it takes place

2. One can infer from the passage that the sunset looks yellow because

(A) scattering does not play an appreciable role in determining the color of the transmitted light

(B) the blue light is scattered on the long way through the air at that time

(C) the light coming directly from the sun is blue

(D) the air is polluted to such a degree that the Earth’s climate is actually changing

3. As it is pointed out in the passage,

(A) our eyes are more sensitive to light with blue frequencies

(B) the red light passes easily through the air without scattering at all

(C) when the sun sets, only the blue light is left

(D) the sunset is likely to look orange when small particles, such as salt from sea spray, are in the air