WASHINGTON—The number of Americans seeking unemployment benefits fell last week for a fifth straight week to a new pandemic low, the latest evidence that the U.S. job market is regaining its health as the economy further reopens. The Labor Department said Thursday that jobless claims dropped to 385,000, down 20,000 from the week before. The number of weekly applications for unemployment aid, which generally reflects the pace of layoffs, has fallen steadily all year, though it remains high by historical standards. The decline in applications reflects a swift rebound in economic growth and the job market’s steady recovery from the coronavirus recession. More Americans are venturing out to shop, travel, dine out, and congregate at entertainment venues. All that renewed spending has led companies to seek new workers. Employers have added 1.8 million jobs this year—an average of more than 450,000 a month—and the government’s May jobs report on Friday …