Answer:
Consuls could veto each other’s decisions.
Explanation:
In the history of Rome, during the period of Republic consuls had the highest rank in the country, which enabled them to led the army, administrate the political affairs. But, still as the Romans were afraid that the consul could take too much power for himself, they have decided to introduce two consuls, and through that to prevent this type of things from happening. One of days for doing that is the possibility that one consul could veto the decision of the other one.
Harsh climate no irrigation for land is possible
This should help you out.
Just compare a river map of West Africa to a map of West African kingdoms.
You can clearly see that all of these kingdoms form around the Niger River.
More support to this: None of these other rivers are even in Africa: The Thames is in England, the Indus is in Pakistan, and the Euphrates runs through the Middle East.