You are so absorbed watching the movie casablanca with friends that when two people ask if you want a snack, you do not even hear them. when reminded of this later, you realize that you were aware of the movie to the exclusion of everything else. this could be termed a mild:

You are so absorbed watching the movie Casablanca with friends that when two people ask if you want a snack, you do not even hear them. When reminded of this later, you realize that you were aware of the movie to the exclusion of everything else. This could be termed a mild dissociative experience.

it teaches readers about an interesting chinese custom and causes them to determine that the minister is trying to be polite

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.