Final answer:
Assembly lines achieved productivity but at the expense of standard of living.
Step-by-step explanation:
The statement 'Assembly lines achieved productivity but at the expense of standard of living' is True. Assembly lines revolutionized the manufacturing process by introducing mechanization and division of labor. While they increased productivity and efficiency, they also led to a decline in job satisfaction and standard of living for workers. Factory work became monotonous and repetitive, and skilled positions were eliminated, resulting in lower wages and limited upward mobility.