Question

Why non luminous bodies become visible when light from other sourcemade to fall on them

Answer 1

Because those non-luminous bodies reflect Light which fall over our eyes

Answer 2

NON LUMINOUS BODIES BECOME VISIBLE WHEN AN OTHER SOURCE MADE FALL ON THEM BECAUSE :

} THE LIGHT FROM THE LUMINOUS OBJECT GETS REFLECTED ON THE NON LUMINOUS OBJECT MAKING IT VISIBLE