From what source does heat mostly come?
Heat mostly comes from the sun, which is also the source of light.
What is said of the heat and light from the sun?
Heat and light from the sun come together in the sunbeam.
From what other source is heat obtained?
Heat is obtained from the burning of any substance.
What else does the burning of any substance produce?
It often produces light.
Can the light and heat from the sun easily be separated?
They cannot easily be separated.