Alice, a five-year-old, used to cry and protest whenever her mother took her to the dentist for dental checkups. however, after a few visits, alice stopped crying, even though she still does not like going to the dentist. this change in alice's response to dental visits is an example of

This change in alice's response to dental visits is an example of "habituation".

Habituation is an extremely straightforward type of learning, in which a creature, after a time of introduction to an improvement, quits reacting. The most intriguing thing about habituation is that it can happen at various levels in the sensory system. Tactile frameworks may stop, sooner or later, sending signs to the mind because of a constantly present or regularly stimulus. Absence of proceeded with reaction to solid smells is a typical case of tactile home. Habituation to complex stimuli may happen at the level of the mind; the upgrade is as yet seen, yet the creature has essentially "decided" to never again focus.

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.

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."