Além de fazer comércio de produtos, considera-se que os berberes estimularam as trocas culturais entre as regiões ao norte e ao sul do deserto do Saara. Essas trocas culturais aconteciam porque: A- os berberes somente comercializavam com povos que tinham idioma e cultura semelhantes entre si. Por isso, as trocas eram possíveis. B- nos contatos para praticar o comércio entre sociedades distantes, os berberes também levavam informações sobre crenças, costumes e ideias, ampliando o conhecimento que um grupo tinha sobre outro. C- os berberes impunham sua cultura aos povos com os quais faziam comércio. Por consequência, esses povos trocavam obrigatoriamente seus hábitos e suas crenças. D- os berberes mudaram completamente sua cultura em razão das trocas culturais que incorporaram no contato com os povos do norte e do sul do Saara com o qual comercializavam.

- "the civil rights movements"

- "following the american civil war and abolition of slavery, the united states entered a period known as reconstruction, during which black americans continued to suffer from disenfranchisement, racial segregation, and economic oppression. beginning in the early 1950's, black americans launched a series of major campaigns of civil resistance, emphasizing the need for nonviolent protests and civil disobedience."

"such as the montgomery bus boycott of 1955-56, a campaign launched by rosa parks against the policy of racial segregation of the public transit system in alabama. “sit-ins” became popular across the american south, particularly in greensboro, north carolina, increase national sentiment."

- "the counterculture movement"

- "counterculture began to develop in the united states following the rise of conformity in american culture during the 1950s. by 1963, youth, particularly those of the white middle class, began rejecting the cultural standards and normality of their parents, opting for progressive attitudes instead. the movement gained momentum as the civil rights movement became increasingly successful and as the u.s. military intervention of vietnam began to take a negative turn."

"hippie counterculture moved further into popular culture following the summer of love in 1967 when thousands of people came together in the haight-ashbury neighborhood of san francisco. along with greenwich village in new york city, haight-ashbury became a hub for the counterculture movement."

the fact that could also be added to column b is that during world war ii, specifically between the years 1941 and 1945, japan expanded its territory towards the indonesian territory in what was known later as part of the "pacific war". in that time, japan could conquer the philipines, singapore,   borneo, central java, malang, cebu, sumatra and various other islands of the area, therefore expanding its territory for a brief period of time.

the governor can not veto a referendum that the voters approve