What is the Rotation of the Earth? (Fill the gaps)

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
It is the of the around its own . It lasts slightly less than hours and it causes the succession of and .