What did you understand most/least about today's lesson and independent practice?

Today's test was rather easy. I understood the part about the extensions the most. I find the extensions easy because the extensions are basically abbreviations of what the extension stands for. The most difficult part was the virtual index. I found it difficult because I was absent on the day that lesson was taught. Also, it was difficult because I was here for everything else which made those questions easier. These are the questions I found hardest/easiest.