46% knows the answer to this question: "When plaque hardens on your teeth what does it form? "

And do you know the answer to this one? "On which continent is Belgium located?"

80% knows the answer to this question: "What is the historic Slavic title of a Russian, Bulgarian or Serbian monarch? "

And do you know the answer to this one? "Hong Kong was returned to which country by the British in 1997?"

66% knows the answer to this question: "A chameleon is famous for changing its color. Can you change pace and identify the type of animal it is? "

And do you know the answer to this one? "In 2013, China announced an air defense zone that overlapped with that of what country?"

82% knows the answer to this question: "Which US state did William Penn found? "

And do you know the answer to this one? "What number is equal to Roman numeral V?"

65% knows the answer to this question: "Which word is spelled wrong? "

And do you know the answer to this one? "What web site, which allows you to make video calls over the web, gets its name from "sky peer-to-peer"?"

54% knows the answer to this question: "Who sang the famous song ”I Feel Love” (1977)? "

And do you know the answer to this one? "Who sang the famous song ”Lyin’ Eyes” (1975)?"

30% knows the answer to this question: "The guillotine was invented in which country? "

And do you know the answer to this one? "Outlawed from a Viking settlement in Iceland, who went on instead to settle Greenland?"

77% knows the answer to this question: "At what age did girls typically marry in ancient Athens? "

And do you know the answer to this one? "Washington D.C. was originally founded near which river?"

83% knows the answer to this question: "Which is the complete name of famous businessman Onassis? "

And do you know the answer to this one? "Which of these do Mexico, England and China have in common?"

62% knows the answer to this question: "Which of these was one of Abraham Lincoln's nicknames? "

And do you know the answer to this one? "Which form of transportation was invented first?"

35% knows the answer to this question: "Kobe Bryant was born in 1978. Which sport is he famous for playing? "

And do you know the answer to this one? "Shakira was born in 1977, but what occupation is she famous for having? "

85% knows the answer to this question: "Who had a dream that his "four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character"? "

And do you know the answer to this one? "Which of these items is a real artifact?"