Answer:
The answer is C. Sympatric Speciation via polyploidy
Explanation:
Among all various forms of speciation that exist, the most rapid is sympatric speciation which occurs when a population becomes separated in terms of reproductivity. The process of offsprings developing with more than the common number of chromosomes is referred to as sympatric speciation via polyploidy and it is this process that makes this speciation rapid.
It would refer to a number of related phenomena and patterns of change.
The trolleys have been reduced over the last decades, after their initial increase as a public transportation, when new and better ways were discovered/produced for transport, their decline has started.
The buses since their invention, had grown in number and became a very important part of every city's public transportation, and still are.
The rapid transit is the most recent one of the mentioned in here. It's popularity has grown, number increased, and is very practical because it is not causing traffic mess. It is very important transport asset nowadays and makes lives of millions of people much easier.
It is called surface currents.
The statement is correct.
The contour lines are a very good indicator of the relief. The closer they are to one another, the steeper the relief, and vice verse, the more distant they are from one another, the flatter the relief is.
In general, contour lines that are very close to each other can be noticed on the mountains, as most of the mountains have steep parts, or rather steeper slopes.
The more distant contour lines, on the other hand, can be found on places like the valleys or the plateaus, places that in general are much flatter.