Definition: This disease, which attacks the natural defense systems of humans, burst onto the scene in the 1980s.

Aids.

Explanation:

AIDS epidemic during the 1980's had a substantial impact on the people and the economy of several nations. The first case of AIDS was reported in the year 1981 in the United States. This number hugely increased during the decade of 1980's and came to an end in the later phase of 1990's. The greatest impact of the epidemic could be seen among men, who had s-ex with men and among minorities.

yes it is different; your family is right : )

explanation:

a fair is where you purchase things while a carnival is where people are on the streets in carnival