Low dissolved oxygen concentrations that occur in many bodies of water when nutrients stimulate the growth of algae that subsequently die and are decomposed by oxygen-using bacteria.
Many people still think that United States is still a leader of the free world.
<u>Explanation:</u>
Even after the end of the colonization in the world and with the end of the cold war between the United States of America and the USSR, some people still think that the United States is still the leader of the countries in the free world.
The way with which the United States rule is with the trade policies of the country towards the other countries or the strong financial position of the country.
Answer:
The best answer is mountains and valleys
Explanation:
first option doesn't seem correct because it doesn't have one giant plateau. Instead it is multiple. so that option is incorrect.
second option is incorrect because there really is no evidence about plains and hills.
third option is incorrect for the same reason as second option.
The Fourth option is correct because Sub-saharan contains mountain ranges and multiple rift valleys.
(have a nice day and soon merry christmas or happy Hanukkah)
Answer:
Seafloor spreading results from intense activity in the upper mantle which cracks the crust and pushes it away.
Explanation:
Seafloor spreading is a process that was first noticed by Alfred Wegener and was used by him in his theory of plate tectonics. There are three types of plate boundaries; convergent boundary, transform boundary, and divergent boundary. The last one is the one where seafloor spreading occurs.
The convection currents in the mantle are the process that breaks up the crust and move the tectonic plates, and when there is higher activity than usual at some place it results in break up the crust of an already existing tectonic plate. Basically, magma rises at a higher rate and pushes through the crust, in this case, the oceanic crust, and it manages to gradually break through it and come out on the seafloor. By doing so, the magma and the pressure from below are pushing the two now divided parts of the plate. As the space between the two different parts becomes larger and large the density of the crust becomes smaller and smaller so more and more magma rises through. The magma quickly solidifies on the ocean floor and piles up, thus creating an underwater mountain range known as a mid-ocean ridge.
Answer:
because urban areas are cenralized thus allowing one reach a bigger market
Explanation:
