Interior of a large sanitary sewer viewed from an access manhole. In the developed world, sewers are pipes from buildings to one or more levels of larger underground trunk mains, which transport the sewage to sewage treatment facilities.
Free trade is a policy followed by some international markets in which countries' governments do not restrict imports from, or exports to, other countries. Free trade is exemplified by the European Economic Area and the North American Free Trade Agreement, which have established open markets. Most nations are today members of the World Trade Organization (WTO) multilateral trade agreements.
NAFTA Resources. NAFTA is the world's largest free trade agreementâso large, it took three Presidents to implement it. Created to help the U.S., Mexico, and Canada compete with the European Union, it has tripled trade, but also been criticized for outsourcing American jobs. Here are the facts about its history, purpose, pros, and cons.