Circus Oz, a satirical circus that turned 21 in 1999, comes from which country nicknamed "Oz"?

Who painted "Girl with a Pearl Earring" around 1665? Around 1800 Josiah Spode II perfected which type of ceramic made with bone ash? Around 1860 Robert FitzRoy of Britain's weather office rejected "prediction" and "prophecy" in favor of which word? Circe turned the men of which seafarer into swine? In 1991 former Soviet republics formed the CIS, the Commonwealth of what? Which leader divorced his wife Winnie in 1996? In 1990 Citgo became wholly owned by the state oil company of which country? Which man announced his resignation as U.S. secretary of defense in December 1993?