Answer: a. all older oceanic crust has been subducted into the mantle
Explanation:
Oceanic crusts are generally not known to survive as long as that of one found in the Mediterranean sea which is said to be more than 300 million years old. This is because approaching 200 million years old, oceanic crusts go back into the mantle at subduction zones in a process that can most accurately be described as recycling.
It is said that the oceanic crust in question is so old that it may have been part of Tethys, one of Earth's earlier oceans.
Answer: Adding minerals to Distilled Water and Reverse Osmosis helps increase the PH of the water
Explanation:
Answer:
When it comes to 18 all I can say is that the cities are near the border in the warmer, more fertile areas of the country. A lot of the area is still cold, plus the closeness to the USA adds an economic advantage. So for #18, it's because of the fertile growing land and proximity to its closest trading partner. For #19, I'd say they're close to the ocean for one. Mexico trades oil on a global scale, so the richest places are on the ocean/seas. This differs from Canada who trades a lot with the USA, so their trade lcoations are close to the USA. Meanwhile Mexico uses considerably more sea trade, therefore their better cities are closer to the ocean/seas.
Explanation:
AP Human Geography and a bit of logic. it's a rough answer and I'm not sure it's right but I feel like it answers the questions.