主要是因为这段搞不清楚
If the visa office you have specified for processing your application is not the visa office responsible for your country of nationality, provide proof that you have been lawfully admitted for a period of at least one year to a country for which the specified visa office is responsible.
Proof of lawful admission is in the form of a stamp in the passport or a status document issued at the Port of Entry or other place of admission. If an extension of the original status has been obtained, the evidence required would be a document or stamp issued by the ministry responsible for immigration matters, providing an extension up to one year or beyond.
Please note that the CPC-Mississauga is not a visa office. Visa offices are outside of Canada.