Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
Admitted for 180 days â Canadians admitted in âVisitor for Pleasureâ or B-2 status without a B-2 visa in hand are deemed to be admitted for 180 days under current US Customs and Border Protection (CBP) interpretation of the rules.
If you are not a citizen of one of the listed countries, then you do not need to apply for a temporary resident visa. Typically a temporary resident visa is issued for up to 6 months. There are circumstances where visitors stay for longer than a 6 month period, discussed below. If you require a visitor visa before entering Canada, there are a number of factors that CIC will consider when reviewing your application.