Limestone is a sedimentary rock that is composed primarily of calcite. It forms from both the chemical precipitation of calcium carbonate and the transformation of shell, coral, fecal and algal debris into calcite during diagenesis.
To calcu-late the PPF, suppose that Crusoe puts all 8 hours into gathering fruit, so that he gets 36 pounds. But there is no time left for fishing, so he gets 0 pounds of fish. If he takes an hour off from gathering fruit, he gets 35 pounds of fruit and has an hour in which to fishâso he gets 4 pounds of fish.The rest of the PPF is con-structed similarly. 2.ut there is no time left for fishing, so he gets 0 pounds of fish. If he takes an hour off from gathering fruit, he gets 35 pounds of fruit and has an hour in which to fishâso he gets 4 pounds of fish. The rest of the PPF is con-structed similarly. 2.
In 1665, the English scientist Robert Hooke used a microscope to examine a thin slice of cork. Hooke described it as consisting of âa great many little boxes.â These âlittle boxesâ reminded him of the cubicles or âcellsâ in which monks lived, so he called them cells. What Hooke had observed were actually the remains of dead plant cells.