I taught middle and high school social studies for 18 years, during which time I also taught expository, academic writing. This was a really handy tool. I would usually ask for a volunteer to do the first one (so the whole class could hear an example), and then, I'd ask the class to complete the remaining practice sentences on their own, then discuss with a partner and make any necessary corrections, and then share out at the end with the entire class. My student's topic sentences in essays always improved after using this handout!