The theory that suggests that successful aging occurs when people maintain the interests and activities they pursued during middle age and resist any decrease in the amount and type of social interaction they have with others is known as

Activity theory

Explanation:

This theory states that elderly people have to stay active and maintain social interactions.  It helps to replace lost life roles after retirement. It says that they will receive life satisfaction if they are active somehow

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.

stewards ice box was the purchase of alaska from russia and it was called that because people thought it was not a good idea to purchase alaska