Visible light is a type of mechanical wave.

Light is an Electromagnetic wave that also include, Ultraviolet Rays, X-rays, Radio Waves, etc.

The offspring will be blood type aa, bb, ab and oo or i

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the