I believe the correct word to fill in the blank is water. In moist climates, water tends to dissolve limestone near the surface, resulting in cave formation since limestone is soluble to water. Hope this answers the question. Have a nice day.
1. is A. soil
And the last one I would go with is remains the same just in different forms tbh
The correct answer is - Basins.
The basins are areas made out of folded rock layers that have the appearance of a bowl turned right-side up. The basins lie between two or more higher relief forms, very often horsts. They are lowlands, usually flat in most part, with sudden steep sides. Their size can very significantly and it depends on the geological activity in the particular place.
