Thank you for your response, but the problem is that Screen Options doesn’t function in Edit Page mode. Neither does Help.
Both worked previously. The only thing that seems to be different is that in Screen Options I chose “one column” instead of the default “two columns.” (I did that thinking it might get rid of the Archive and Meta areas on the right of the pages; obviously, I was wrong about that.) After choosing “one column,” neither Screen Options nor Help display when selected.
When I hover over the Screen Options and Help buttons, I get the correct URL on the bottom left of the pages. My guess is that there is something about the one-column layout that doesn’t permit them to be displayed. That’s just a guess though. But since I can’t access Screen Options, I can’t reset Pages to two-column.
Again most sincere thanks for your kind response. Any further suggestions will be greatly appreciated.