Answer:
C. It is radiation leftover from the Big Bang
Yes you should if you will like to. It is your opinion so follow your dreams if they are your dreams.
The frequency of the wave has not changed.
In fact, the frequency of a wave is given by:

where v is the wave's speed and
is the wavelength.
Applying the formula:
- In air, the frequency of the wave is:

- underwater, the frequency of the wave is:

So, the frequency has not changed.
Heat comes from the movement of molecules so it's B
Answer:
Equator
Explanation:
The equator is the line of latitude that separates the earth into the northern and southern hemisphere.Its magnitude is 0 degrees latitude. The equator and other lines of latitude are parallel to each other. The lines of longitude which is 0 degrees is known as the Greenwich meridian. The longitudinal lines however are not parallel as they converge at the poles.