The u. s. congress banned trade with which of the following countries in response to the policy of apartheid? nicaragua south africa el salvador soviet union

The U.S. Congress banned trade with South Africa  

Explanation:

With the end of the Apartheid Act of 1948, which was an extended part of racial discrimination that existed earlier, the foreign relations with U.S. had come to an end.  The attempt to integrate South African supremacy over Southern Africa has failed in the year 1970, which put an end to the foreign intervention in Angola and Namibia.  

As a result of Sharpeville Massacre, South Africa was abandoned from UN for their apartheid policies. US congress forced in maintaining distance between the two countries in almost every aspect as well as trade.

d. it was created with the idea that it could be easily revised if it was ineffective

the columbian exchange, also known as the columbian interchange, named for christopher columbus, was the widespread transfer of plants, animals, culture, human populations, technology, and ideas between the americas, west africa, and the old world in the 15th and 16th centuries, related to european colonization and trade following christopher columbus's 1492 voyage. invasive species, including communicable diseases, were a byproduct of the exchange. the changes in agriculture significantly altered and changed global populations. the most significant immediate impact of the columbian exchange was the cultural exchanges and the transfer of people between continents.

the new contact between the global population circulated a wide variety of crops and livestock, which supported increases in population in both hemispheres, although diseases initially caused precipitous declines in the numbers of indigenous peoples of the americas. traders returned to europe with maize, potatoes, and tomatoes, which became very important crops in europe by the 18th century.

the term was first used in 1972 by american historian alfred w. crosby in his environmental history book the columbian exchange. it was rapidly adopted by other historians and journalists and has become widely known.