Benjamin franklin: ordered the mapping of the gulf stream created the first tide-prediction machine improved travel between the colonies and africa all of the above (i am to tried to do the questions)

Improved travle between colonies and africa

The correct answer is b, social stratification is needed for a society to exist. marxist theory regarding social stratification is that due to the differing economic capacities among people in society, a natural separation occurs between those that own the means of production and those that sell their labour in the production chain.