The length of one day on earth is determined by how long it takes

1) the moon to revolve once
2) the moon to rotate once
3) earth to rotate once
4) earth to revolve once

i need the answer fast

Drastic boundary changes can occur for all of the following reasons except for a. a shift in the way a river flows b. the collapse of a government system c. a conflict between two neighboring groups d. one country's decision to sell land to another country select the best answer from the choices provide

8. compare the education of a sparta boy and an athenian boy. (2 points)

Why did the belgian parliament pass laws to decentralize its government? a. to increase trade with neighboring luxembourg b. to decrease the political power enjoyed by the flemish c. to enable belgium to join the european union d. to reduce tensions between belgium's two main ethnic groups