Pls help me its in the picture

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

Business and industries in the 1920's most closely followed the buying demands of a) the government b)farmers c)consumers d)manufactures

Select the correct answer from the drop-down menu.during the (scientific revolution, renaissance, industrial revolution), european intellectuals rejected many teachings of ancient scientists promoted by the church. to replace flawed theories, scientists began researching and conducting experiments. they used critical and reasonable thinking to draw concrete conclusions. this also led to the (scientific revolution, industrial revolution, enlightenment). it was an age that focused on using reason for understanding laws of nature and identifying humans' natural rights.