European overseas expansion led to the rise of colonial empires, producing the Columbian Exchange. The combination of resource inflows from the New World and the Industrial Revolution of Great Britain, allowed a new economy based on manufacturing instead of subsistence agriculture.
What resulted from Europe's exploration of the New World?
the rise of colonial empires

Besides increased efficiency of power plants, there was an increase in efficiency (between 1950 and 1973) of the railway utilization of this electricity with energy-intensity dropping from 218 to 124 kwh/10,000 gross tonne-km (of both passenger and freight trains) or a 43% drop. Since energy-intensity is the inverse of energy-efficiency it drops as efficiency goes up. But most of this 43% decrease in energy-intensity also benefited diesel traction. The conversion of wheel bearings from plain to roller, increase of train weight, converting single track lines to double track (or partially double track), and the elimination of obsolete 2-axle freight cars increased the energy-efficiency of all types of traction: electric, diesel, and steam. However, there remained a 1215% reduction of energy-intensity that only benefited electric traction (and not diesel). This was due to improvements in locomotives, more widespread use of regenerative braking (which in 1989 recycled 2.65% of the electric energy used for traction,) remote control of substations, better handling of the locomotive by the locomotive crew, and improvements in automation. Thus the overall efficiency of electric traction as compared to diesel more than doubled between 1950 and the mid-1970s in the Soviet Union. But after 1974 (thru 1980) there was no improvement in energy-intensity (wh/tonne-km) in part due to increasing speeds of passenger and freight trains.
What caused the energy efficiency to go up?
energy-intensity dropping

Meanwhile, producer Joe Pasternak, who had been successfully producing light musicals with young sopranos for Universal's German subsidiary, repeated his formula in America. Teenage singer Deanna Durbin starred in Pasternak's first American film, Three Smart Girls (1936). The film was a box-office hit and reputedly restored the studio's solvency. The success of the film led Universal to offer her a contract, which for the first five years of her career produced her most successful pictures.
Who starred in the film Three Smart Girls?
Deanna Durbin