Why do you apply for American transit visa?

你办美国过境签证的理由是什么？

I have got a transit visa and I can go out of the airport, right?

我已经通过了过境签证，可以离开机场了，对吗？

Transit Visa: is required for persons travelling through Canada for less than 48 hours on their way to another country.

Transit Visa过境签证：用于旅行至其他国家时过境加拿大且停留不超过48小时。

Answer: : There are 3 requirements: 1) Citizens from the 45 countries under the 72-hour Transit Visa Exemption Program;

答：需要具备3个条件：（1）属于72小时过境免签范围的45个国家公民；

Answer: : a foreign national with the 72-hour transit visa exemption is not allowed to leave the city where the stopover is permitted.

答：办理72小时过境免签手续的外国人不得离开准予其停留的城市。