Dear Spikes2003,
Thank you for your advice. Unfortunately, your first suggestion is both very time-consuming (with a slow connection - I live in a rural area) and can have undesired effects - I tried clicking on what thought might have been a scrolling-down button and found that it negatively affected the number against the comment in question, even though I totally agreed with what the comment said. I don't want to do worse things by just randomly clicking!
Your second piece of advice would be helpful if I could find the QA section with explanations to which you refer. I have gone to the help section but can only find FAQs, which (so far) consist entirely of UNANSWERED questions. Please could you explain where the clear explanations to which your refer are located?
Thank you.