River systems were important to the development of the United States because they (1) allowed Americans to travel easily between the east coast and the west coast
(2) prevented foreign invasion of United States territory
(3) provided routes for shipping agricultural and manufacturing products
(4) made the southeast the major destination for immigrants

the old way of life was represented by superstition, an angry god, and absolute submission to authority. the thinkers of the age of reason ushered in a new way of thinking. this new way championed the accomplishments of humankind. individuals did not have to accept despair. science and reason could bring happiness and progress. kings did not rule by divine right. they had an obligation to their subjects. europeans pondered the implications for nearly a century. americans put them into practice first.

answer; genetics;

the first question's answer is a.