How Native Americans were impacted by the growth of the United States at 1783 - 1853) ?

Which pronoun has an unclear antecedent in the following sentences? the sixth-grade students liked volunteering their time to read to the elderly people in the hospital. it made them happy. a. their b. it c. them d. no unclear antecedents

Lots of points: economics: the is the dollar value of all final goods and services produced within a country’s borders within a given year. a. gross domestic product b. business cycle c. inflation rate d. net exports

Which statement about spreading knowledge of diseases and health around the world is correct?