I looked at the Firefox tab video and brought up the Firefox home page, but now I am at my home computer and I do not want to download Firefox.
thing 17: However, I was surprised to find that I could add tabs without downloading, so I actually add a tab or two and that was very convenient, especially since my home computer puts all of the IE tabs in one clump at the bottom of the screen, making these exercises even more challenging.
Thing 18: I assume that you must have Firefox downloaded to add an add-on. Forgive me if I am mistaken. (I am not back at work until Tuesday.) I did look at the add-on possibilities and tried one (Ad blocker) getting the message about special software needed to proceed, etc. I declined.
I also viewed some of the search engine option. I hope this counts for something.
Thing 19: Text size. Well...see first paragraph. I did check the Firefox home page to see if that were possible like the tab option, but I couldn't identify a possibility.