There are 4 different flipcharts. At the beginning of each flipchart I include a brief review of important academic vocabulary words with examples. I randomly call on students to fill in the blank for the correct vocabulary word. The answer is on the next slide. As I taught different concepts, I added to the original flipchart (which is why there are 4 different ones). I use this regularly (at least once a week) to help students learn their vocabulary and retain it. It doesn't consume much time.