Buna is a census-designated place in Jasper County, Texas, United States. The population was 2,142 at the 2010 census.
Gas Exchange. Gas exchange is the process by which oxygen and carbon dioxide (the respiratory gases) move in opposite directions across an organism's respiratory membranes, between the air or water of the external environment and the body fluids of the internal environment.
foreign exchange. noun. Tweet. : the process by which people in different countries pay each other by exchanging different types of money. a process of settling accounts or debts between persons residing in different countries. 2. : foreign currency or current short-term credit instruments payable in such currency. See foreign exchange defined for English-language learners.