Why is the sky blue in the morning and black at night?

a clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. when the sun sets we see red and orange colors because the blue light has scattered and away of the sight of

explanation:

away from the curb

explanation:

the wheels would then hit the curb if it started to rolling, decreasing the chance of an accident.