Around 1621 William Oughtred invented which calculating device, found in engineers' shirt pockets well into the 20th century?

About 10,000 years ago, what dug out many of Minnesota's "10,000 lakes"? About 100,000 people greeted which aviator at Le Bourget airfield when he landed there in 1927? Which sea, about 1,200 miles long, has a maximum depth of almost 10,000 feet? Which country has the largest Arab population? About 180,000 Black soldiers served in the Union Army. Sgt. William Carney was among the first African Americans to ear… Around 1855, who popularized the laboratory burner now named for him? About 2 million people visited which 984-foot landmark in its first year, 1889? Custer's men faced about 2,000 warriors of many tribes, including Cheyenne and which largest group?