Someone please help will mark as brainliest

Why is it useful for historians to base certain studies on the analysis of historical periods

The decision to annex hawaii was a controversial one

Which sentence best explains how steam power changed agriculture in england between 1810 and 1850? a. farmers started using steam-powered machines to spray chemical fertilizers and pesticides. b. livestock farmers began using steam-powered machines to milk cattle and shear sheep. c. steam-powered railways transport and sell agricultural produce far from where it was grown. d. steamships to transport large numbers of people from the united states to english farms.