only part of the energy in one trophic level gets passed to the next level. in any energy pyramid, about is passed from level to level.

a) 10%

b) 30%

c) 50%

d) 90%

A) 10% 
As little as 10% percent is passed from one tropic level to the next.
The majority of it is lost. 
Hope this helps!

Earthquakes and tsunamis

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.