1. why might it be necessary to amend the constitution?
2. what is the "elastic clause" and why is it important?

answer would be b, a tariffs main purpose is to protect domestic production and jobs.

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.