The correct answer is - A) Permafrost used to be permanent.
The permafrost used to be permanent until recently, so using certain techniques of building on it functioned properly. But with the climate changes that are becoming more and more evident, the permafrost is no longer permanent, but instead, it is either defrosting in some part of year and then forming again, or has been totally absent from some regions in the present.
That has caused changes in the rules governing building on permafrost. The reason for the changes is that the old techniques do not work properly anymore, and the permafrost changes are making change in the landscape, making big damages on the infrastructure in meantime.
<span>Permafrost used to be permanent.
Due to increased temperatures (global warming), permafrost is thawing in areas where it once was permanently frozen.</span>
category 1 can be more destructive than category 5
Explanation:
category 1 happens more than category 5, those are rare. Category 1 can dump a lot of rain and cause a lot of damage by creating floods and landslides. It knocks down trees, etc.
A fall line is an upland region of the coastal plains meets and the term states that lots of rivers fall from this Piedmont to the coastal plain making rapids with waterfalls.
These falls are important as for the settlement as they block the ocean going ships from entering in any further upstream and also provided water power to run the region industries.
