Answer - Ground water erosion is a type of carbonic acidic water. That goes into the holes thru the soil and pretty much cracks thru rocks.
20. The answer is 1 (Precambrian)
21. The answer is 4 (Pennsylvanian)
22. The answer is 2 (Bony Fishes, Dinosaurs, and Mammals)
23. The answer is 2 (Reptiles)
C. The liquid in Beaker A is not as dense as the liquid in Beaker B.
Solar eclipse
Ignore this need to get 20 characters