If a heat engine pulls 4390.0 j of heat from the hot reservoir and exhausts 3582.2 j of heat to the cold reservoir, what was the work done by the engine? what is the efficiency of this engine in percent? (do not enter the percent sign)

What changes occur in the brain during the teenage years? 25 points, someone me out!a.) thinking becomes slower as the brain grows larger. b.) connections between neurons become stronger and faster. c.) unused neurons fuse together to form larger, better functioning neurons. d.) more neurons are developed.