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.
It typically takes 2â3 business week to get a Canadian visitor visa. It is a two step process: Apply online on CIC website by filling up forms, uploading supporting documents and paying the fees. Within next 1-3 weeks, CIC will evaluate your application details and make a decision.