 The professor's asking questions about how you got the information, where you got the information, dot, dot, dot, dot, dot, dot, dot. That's how you're going to have to do it in the future, because cheating on the Internet, off the chart. The state of history, July 11, 1987, the world population went over 5 billion, with a B, people. Okay? So it was 37 years ago, 5 billion people on the planet. Now it's 8 billion.