http://docs.google.com/View?id=ddw24msz_233dncxcmcb
Homework
5/17-5/18 Why is it so difficult to design a real-scale model of the solar system? LL para
5/19-20- How is gravity important to earth? LL 2 para.
5/21 - On LL What keeps the planets in orbit around the sun? explain LL