Why is trade necessary. write with examples

Trade is necessary to help provide the needs and wants of a country. For example, during the Atlantic slave trade, England would trade textile, and rum to African countries who would give slaves to the colonies. The colonies would use slaves to cultivate crops such as sugar and tobacco to give to England.

the anasazi indians were real pioneers and created roads and irrigation systems for watering their crops. they were also great architects and the cliff dwellings are one of their biggest achievements.

explanation:

yes, since there is a positive and a negetive if the positive and negitive wasn't there wouldn't a flow electricity in it.