"... leading to the development of Modern Magonomic Theory, which is the underpinning of Equestria's economy…"
She put the finishing touches on her chalkboard diagram. A few more relational arrows here, an infobox there with the new vocabulary she'd just introduced, and it was complete.
"... bringing us back to the Ponyville market hub, which is where this all started!"
The end of her lecture was punctuated by the sound of chalk finding its place in the chalk tray, and the clop of her hooves as she turned to the class. Afternoon sun crawled across the wooden floor. A wide ceiling fan spun lazily from the rafters. And her students, two dozen fillies and colts, were staring in rapt attention, as if they couldn't believe what they'd just learned.
At least, that's what she wanted to believe. Really only a fraction were attentive - the Twists, Silver Spoons, and Clodhoppers of the lot, as usual. The rest ranged from typical distracted fidgeting to fully asleep and drooling on their desks.
Still, she put on a practiced smile, and asked, "Any questions?"
A few hooves were raised - as were some heads, off a desk or two. Silver Spoon had a question, probably about some advanced topic she'd read about in her parents' tomes and to which Cheerilee would have no hope of providing a satisfactory answer. That left Snails, Aspidistra, and dear, dear old Apple Bloom. That one wasn't the most attentive sort, and she tended to get in all variety of trouble, but she could at least be interesting - and she was quick on the draw, which made picking her an easier choice.
Cheerilee looked in her direction. "Apple Bloom?"
"Um," the filly hesitated, shifting her red mane about her face. "Are you still single?"
Cheerilee nearly choked, which contributed to the sudden burst of laughter around the room.
Her first genuine line of thought, is this filly asking me out?, would soon be filed away to the Nope section of her brain. The next, is this some kind of prank again?, seemed more realistic and interrogable, but nothing about Apple Bloom's demeanor betrayed such a motive. And she could tell - Apple Bloom was a terrible liar, in contrast to most foals, and much to Cheerilee's relief. That left the last: is this just a genuine question unrelated to my entire lesson plan? Yeah, that was probably it.
Once she'd recovered some scant composure, and the laughing had died down, Cheerilee nodded, and answered in her most didactic classroom voice, "Why, yes, Apple Bloom. I am. Still."
Apple Bloom cocked her head. "And why is that?"
Cheerilee smiled. She would have liked to say, "I'm sure you and your friends doping your brother and me with a love serum had nothing to do with it!", but what she said instead was, "I suppose I just haven't found that special somepony yet." After a second, she added, "... Still!"
Before Apple Bloom could keep this question going, and further strain Cheerilee's patience, she decided to bite the bullet by pointing at Silver Spoon's still-raised hoof. "Ms. Spoon, you have a question?"
Silver Spoon looked overjoyed at finally being chosen, and took a great, deep breath, surely preparing for a lecture of her own to rival her teacher's-
But then there was a noise outside. Heads turned, and students soon rushed to the windows.
"Woah! Look at that!"
Even Silver Spoon was distracted by whatever had happened out there - or was still happening.
Cheerilee announced, "Settle down, class! Whatever it is, it can wait-"
But there the sound was again.
Sweet Celestia's flanks, what was that?