What famous landmark hosts the lighting of its iconic Christmas tree closely after Thanksgiving?

Rockefeller Center

In the "Harry Potter" films, what position does Harry play on his Quidditch team? What female singer had a hit with the song "Girls Just Want to Have Fun"? What layer lies directly beneath Earth's crust? Which journalist led the exposure of corruption of the Standard Oil monopoly in the early 1900s? Which U.S. President famously said, "Mr. Gorbachev, tear down this wall"?