<span>When the surface layer was dug up, the permafrost was exposed. When the weather warmed, this exposed permafrost would have melted and become soggy, causing the ground underneath the tracks to shift.</span>
Building models doesn't actually help scientists observe phenomena. Scientists build models to describe how nature and systems operate then make observations to see if their models match what they observe. Models which don't match what they observe are either alterated or scrapped. Good models are kept and used by the scientific community.
<span>Rex imitates a dog. The lead soldier controls the robot by using simple commands like “stop”, “fetch” and “heel”. It is designed to help the soldiers on operations and missions where it accompanies the lead soldiers from a distance, using the developed technology and patented by IAI. </span>
Natural springs hope this helps :D
