WASHINGTON—The number of Americans seeking unemployment benefits fell last week to 712,000, the lowest total since early November, evidence that fewer employers are cutting jobs amid a decline in confirmed coronavirus cases and signs of an improving economy. The Labor Department said Thursday that applications for unemployment aid dropped by 42,000 from 754,000 the week before. Though the job market has been slowly strengthening, many businesses remain under pressure, and 9.6 million jobs remain lost to the pandemic that flattened the economy 12 months ago. In February, U.S. employers added a robust 379,000 jobs, the most since October, reflecting an economy in which consumers are spending more and states and cities are easing business restrictions. Thursday’s figure, though the lowest weekly figure in four months, showed that weekly applications for jobless benefits still remain high by historical standards: Before the viral outbreak, they had never topped 700,000, even during the …