Pollution in the air causes acid rain. And limestone is a calcium carbonate compound, which is an alkali. So when an acid and alkali mixes together, you get a reaction. Which is dissolution. Dissolutions causes the outside layer to dissolve, resulting in mush.
There is two major hemispheres (The Two Main Continents).
A meta population is a group of separate, isolated populations that have individuals occasionally disperse between the habitat islands, allowing re-colonization of islands that might go extinct. Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.