What did the mandate of heaven in ancient china state

The Mandate of Heaven satiated that the idea that there could be only one legitimate ruler of China at a time, and that this ruler had the blessing of the gods. They used this Mandate to justify their overthrow of the Shang, and their subsequent rule.

South wales composes a lot of coal in that region.

This is all you, but i can give you some topics that you could try. if it rained when you want to do something outdoors, it 'limits' that human activity. maybe you want to do an experiment that goes throughout the whole year and you have to have above freezing the entire year. this 'limits' your activity. i thought of those just off of the top of my head. something that gets to me that might be getting to you is you are thinking too hard about what to do. think simply, and if it is too simple, then bump it up just a little bit.