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.
Stay put for 1,095 days. Once you're a permanent resident, you need to be able to prove that you've been in Canada for 1,095 days out of the past 4 years (there's 1460 days in 4 years, so that's 3 years). It does not have to be 1,095 consecutive days.