** Using WeBWorK **

AHA !
  Q: When is  .  more than just a speck, a period, a full-stop, one-third of ...?
  A: When it is a Perl concatenation.

Thanks Paul !!

(I agree with the recommendation to use a popup menu when the plausible answers are technical words or phrases.  OTOH, I disagree with the occasionally-seen practice of randomizing presentation order within a collection of such menus whose contents use the same strings.)


PS --- immediate context for my query:
    Most of the graphs will be for periodic functions but a few will not.  Instructions are to enter the period (a number) for each which is periodic, but "NONE" (a special string) for those which are not.  For this problem, each figure will now have a prompt  "period = " . ans_rule(5)  aligned (nicely !) beneath it.
    OTOH, I have preliminary design for some problems where those prompts will vary among the figures.