Why is it necessary to add a day to the calendar every four years? A. The rotation of the Earth is actually 24 hours and 6 seconds.
B. The revolution of the Earth is actually 365.25 days not 365 days.
C. The Earth's orbit is elliptical and not circular.
D. The Earth's axis is tilted and slows its rotation.

Which geologic feature would most likely be represented by contour lines john far apart from one another? a cliff a hill a plain a valley

Q: a: in sexually reproducing animals, once fertilization of the egg takes place, the exists as a single cell until cell division begins

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time