What was the first advance in refrigeration technologies in the 1800s? ans: A US patent for refrigeration was filed.

Artificial refrigeration

Explanation:

Artificial refrigeration began in mid 1750s and developed in the 1800s. In 1834, the first working vapor-compression refrigerator was built.

the hollywood film industry of 1950 was threatened on several different fronts. television broadcasting was rapidly becoming the dominant entertainment medium in the united states. the paramount anti-trust consent decree requiring separate ownership for production companies and theater chains had gone into effect on 1 january 1950. large numbers of young men and women were marrying, having children, and moving to the suburbs, which affected the viability of downtown first-run movie theaters. foreign revenues were endangered by protectionist tactics including quota systems, high taxes, and blocked funds. finally, the morality and patriotism of hollywood films and filmmakers were under attack from government, religious, and citizens' groups.

explanation: