Which is the best explanation for why approximately 3,000,000, american women joined the workforce in 1918? a) they joined the workforce because of the effects of the great depression. b) they joined the workforce to offset the labor shortage caused by america's involvement in world war i. c) they joined the workforce because the 19th amendment made it illegal for employers to discriminate against females. d) they joined the workforce because the immigration act of 1917 caused a labor shortage in northern industrial cities.

B. They joined the workforce to offset the labor shortage cause by America’s involvement in World War I. This is because the men went to war and the government allowed women to take their place temporarily. This started to change people’s minds about allowing women to work. Women were very helpful during the war because they took over in factories that sent supplies to the soldiers.

answer:   migrations were important in the neolithic period. "two major migrations passing through southeastern europe were confirmed by the means of archaeo-genetic studies."

the first migration was the early neolithic period -- 6,000 before common era (bce) -- when the first farmers, from anatolia -- asia minor -- spread through europe. the second migration occurred during the early bronze age (3,000-2,500 bce) when the so-called "steppe population," from the eurasian steppe, replaced much of northern europe's previous population.

the first farmers of northern and western europe passed through southeastern europe with limited hunter-gatherer genetic admixture, which occurs when two or more previously isolated populations begin interbreeding. however, some groups that remained mixed extensively -- without the male-biased, hunter-gatherer admixture that prevailed later in the north and west, according to latest discoveries. southeastern europe continued to be a nexus between east and west, with intermittent genetic contact with the steppe people up to 2,000 years before the migrations that replaced much of northern europe's population.

"in some places, hunter-gatherers and incoming farmers seem to have mixed very quickly," says iain mathieson, a geneticist at the university of pennsylvania, who was first author of the paper. "but, mostly, the two groups remained isolated, at least for the first few hundred years. these hunter-gatherers had been living there for thousands of years, and it must have been quite a shock to have these new people show up -- with a completely different lifestyle and appearance."