I've noticed this throughout the lessons, plurals are IMPOSSIBLE to distinguish. I listened to this multiple times and not once was there any indication that this was plural. Sometimes you can figure it out using context clues like sont instead of est but it is amazingly frustrating when attempting to listen to a sentence to determine what it means only to find out there were hidden plurals. I doubt native french speakers skip the last syllable of every word so the tool to teach those words should reflect this. PLEASE FIX THIS DUOLINGO!