Fetch
(sry have to make an answer 20 characters /!:!27837)
The Use of nitrogen fertilizers near the lake is your answer.
Three variables can be used .
1. Sun 2. Moon 3. Earth
These are suggestions that lizzie can control:
1.<span> Discover how long the Earth takes to orbit the Sun
2. how many hours it takes the Earth to spin around once on its own axis, 3. how long the Moon takes to orbit the Earth</span>
You may want to let them know about there X-ray but after you should assure them that there is a solution and you'll both get to it
