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问题是,从美国开车回到加拿大, 顺着公路出美国, 进加拿大, 不经过美国的 the port of entry.

只经过加拿大的 the port of entry. There is no chance to talk to a US CBP officer at the port of Canadian entry.  加拿大入境一边工作人员啥也不记录. So I never have Canadian entry stamp on my Canadian passport. This happened many times.

-It does not matter for your dparture in this case, but when you re-enter US, youi need to go through the port of entry where the US CBP officer can inspect you. 

 咋办?