Well, there are a few types of planetary movement, a planet moves in an elliptical and orbital pattern that can be observed by keeping watch on how many times a year you see it in the sky; with this information you will be able to predict its movement patterns by the frequency of orbital movement as well as the interval between each appearance.
Oh and BTW next time, try posting a SCIENCE question in the Physics category?
They helped by the newly found railroad system and that also led to them figuring the compression out i think
<span>This statement is false, the five main sources of renewable energy cannot all be used to fuel vehicles as technology currently stands. At the moment, cars can be fueled using biomass, hydropower, solar power and even wind energy. However, there is not yet a model fueled by geothermal energy, although there are plans to create such a vehicle in Iceland.</span><span />
Answer:
B. establish communes and promote labor-intensive agriculture