A．The assembly line permits mass production of automobiles.
B．The assembly line enables the workers to be more responsible.
C．The assembly line guarantees the quality of its products.
D．The assembly line helps to arouse the enthusiasm of the workers.

A．The drug promoted the country’s export industry.
B．The drug had a very bad effect on the country’s economy.
C．The drug helped the growth of the country’s economy.
D．The drug saved the people from working.