The mountains have emerged where the tectonic plates meet. The collision of the tectonic plates can disrupt the earth causing earthquakes as well as the growth of a mountain. These mountains take awhile to become the giants they are.
Answer:
The answer is a) oil
Explanation:
Oil, especially in these areas, are abundant. In the past, these areas became wealthy because of oil.
A biggie: the transcontinental railroad. Because it would economically improve wherever it was, both the North and the South competed for the railroad to be in their respective territory, evidenced by the Kansas-Nebraska Act and the Gadsen Purchase and induction of California as a free state in 1860.
In addition: people could get land cheap because it was abundant and might leave to start afresh economically.
There's other stuff I can't remember as clearly, but there's a little and I hope it helps :)
The massive rain forest is one of the major barriers to travel in the Congo region. The correct option among all the options that are given in the question is option "c". This rain forest is very dense in some places and it is almost impossible to pass through it. I hope the answer helps you.
