The equator has no continental borders.
The time for the echo to return is directly proportional to the distance. vw = fλ. In a given medium under fixed conditions, vw is constant, so that there is a relationship between f and λ; the higher the frequency, the smaller the wavelength.
Answer:It’s 5 I believe
Explanation: it says to round to the nearest thousandths, so it’ll be 5.
I think the answer maybe C