Answer:
The air at higher altitudes is colder, less dense, and contains fewer oxygen molecules. This means that you need to take more breaths in order to get the same amount of oxygen as you would at lower altitudes. The higher the elevation, the more difficult breathing becomes
Explanation:
A free-trade zone is by definition “a place where trade is left to happen without tariffs(tax on imports/exports), quotas, or other restrictions”. An example of a free-trade zone is the European Union. There are no tariffs, quotas, or other restrictions placed on trading within the EU countries (they even share a currency). This allows for them to place products at a cheaper price for good quality and still get enough money to grow wealth within the different countries.
