Escavation and soil replacement
Lewis and Clark did map the route to the pacific oceans though they were not able to find a direct water route as they had hoped. The Majority of their trip was along the Missouri River and thus it is the closest thing to a "Northwest Passage" that the explorers were able to find.
, permafrost is ground, including rock or (cryonic) soil, at or below the freezing point of water 0 °C (32 °F) for two or more years. Most permafrost is located in high latitudes (in and around the Arctic and Antarctic regions), but at lower latitudes alpine permafrost occurs at higher elevations. Ground ice is not always present, as may be in the case of non-porous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of the ground material.
The correct answer for this question is this one:
<span>The impact on the christmas island crab population of a very dry season is that their spawning will be lesser than compared to the previous years. The effect of the climate change has a greater one with the crab population.</span>
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