A．Paid much attention to the results of scientific discoveries.B．Seldom introduced safety laws before disasters occurred.C．Hardly ever looked into the causes of tragedies.D．Imposed safety rules as soon as accidents took place.
A．Paid much attention to the results of scientific discoveries.
B．Seldom introduced safety laws before disasters occurred.
C．Hardly ever looked into the causes of tragedies.
D．Imposed safety rules as soon as accidents took place.