Because the earth's climate is CONSTANTLY in flux and what today is a desert was once a tropical forest.
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Answer:
That when there were American troops near their territory the Mexican troops shot at them since Mexico claimed that the Nueces River wascthe Northeastern border(US) while the US said that the Rio Grande was their border so war broke out
In the 1650s, <span>Oliver Cromwell pushed England towards a policy of expanding territory and commercialism.
</span><span>Oliver Cromwell was an English military leader as well as being an important political leader as well. He was the main influence in pushing England towards the policy of expanding.</span>
A decentralized political system
