What is true about air? O cool air rises and warm air sinks
sinking air cools and rising air warms
sinking air warms and rising air cools
O warm air rises and cool air sinks
I will give brainleast!!
Also I have a lot of points!!

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.