I assumed I could do multiple submissions. (Why did I assume this? I don't know.) So I submitted one of my stories. The response page then said "Wait until you get a response before submitting another story." Which makes sense, because they don't want to be overwhelmed with stories.
But I didn't submit my strongest story. Or at least, what I thought was my strongest story. So now I'll be waiting until I get a response before submitting again.
Lesson to be learned: Send in your strongest work.
(Of course, you might be totally wrong, because the writer is the worst judge of her/his own work).
And, does anyone know what the Thaumatrope response times are? :-) [Note that they are not listed on duotrope or Critters Black Holes]