Options: make the taste of food better, produce in small amounts the hydrochloric acid required for the digestion of food, ease the process of cooking, increase the solubility of food particles in water
Options: flow of expenditure devoted to increased or maintaining of the capital stock, expenditure incurred on physical assets only, production exceeding demand, net addition to stock after depreciation
Options: the pressure is the same as that outside, normal atmospheric pressure is maintained by the use of air pumps, the pressure inside is less than the pressure outside, normal humidity and partial vacuum are maintained
Benjamin Franklin was a prolific inventor. He invented the lightning rod, the Franklin stove, studied electricity, discovered the Gulf Stream, started the first library, and on and on. Among his many other inventions, what musical instrument did he invent?