How did many manufacturers in the 1920s improve efficiency to meet increase in consumer demand? They raised prices
They resisted changing production
They offered a smaller variety of goods
They adopted mass production manufacturing techniques

Option: They adopted mass production manufacturing techniques.  

Explanation:  

During the 1920s, American's society and culture changed in developing into new by introducing roaring twenty. It was the first time when Americans introduced to new appliances. Demands also increased because they made people life easier. There was a growth of opportunities to buy automobiles, new gadgets, the washing machine, the radio, instant camera, jukebox, television, refrigerator, electric razor, and in medicines. Manufacturers were able to produce and meet the demands of people because of mass production. Many of the industries adopted the assembly lines for production.    

answer-the island had airfields that the u.s. military needed.

to extend a country’s power and influence