Another Ice Age occurred.
A major volcano erupted in Africa.
A severe drought occurred.
The correct answer is that another Ice Age occured and contributed the most to human migration more than ten thousands years ago.
The Earth was going through an Ice Age phase more than ten thousands years ago and during that period as a result of the lower level of the seas along with the large ice masses, numerous land-bridges arised. Humans capitalized on those land bridges and used them to migrate to new territories.
c. has two houses.
b. is one-chambered.
d. is half Republican and half Democrat.
It is not the United Nations. The correct answer is B. Each individual country
The Spanish Civil War started in July 1936 with the military coup leaded by General Franco, which started a rebellion against the democratically elected Republican goverment. Since the establishment of a Republic and the abolition of the monarchy in 1931, mostly left-wing parties and progressisf leaders had won the elections.
The most conservative sectors of the army followed the fascist general Franco who, during the war, received the support of Hitler and Mussolini, specially, of their aviation military units. The democratic European states refused to help the Spanish Republic and only the URSS contributed by sending some armament.
The war ended in 1939 with the victory of the fascists and the establishment of a military dictatorship that would last until the death of Franco, the dictator, in 1975.