There is a great deal of research that suggests taking a quiz immediately following a lesson SIGNIFICANTLY improves long term retention of the information.
https://en.wikipedia.org/wiki/Testing_effectThus, we encourage you to take the following quiz. Note, these questions are difficult and you should not worry if you get them wrong. Just take the time afterward to review the explanations of the correct answers. The act of taking the quiz goes a long way towards helping you retain this information. We made the questions difficult so that you can learn something new from the answers.