I don't understand "将来入籍又怎么知道我们登陆了呢? "
If you have not landed, when you come to land, you will go through the landing procedure and you will get a stamp on your passport and a PR card later.
If you have landed and don't want Canada government knows that you left Canada, it might be possible if you cross boarder by land. However, it is not easy to hide things from government, at least in my point of view. You need to tell the dates you leave and come back when you fill out the application form. Whatever you write on paper is supposed to be true.
If you have not landed, when you come to land, you will go through the landing procedure and you will get a stamp on your passport and a PR card later.
If you have landed and don't want Canada government knows that you left Canada, it might be possible if you cross boarder by land. However, it is not easy to hide things from government, at least in my point of view. You need to tell the dates you leave and come back when you fill out the application form. Whatever you write on paper is supposed to be true.