Back when I was in undergrad or high school, I had a couple of teachers who asked, the first thing before starting class, was
"What did we learn last class?"
We just sat down, nothings on the board yet. Sometimes, it was on a Monday right after the weekend. Other times, it was right after attending 2-3 other classes.
Everyone would pull out their notes, folders, binders, documents. And we would name off everything we covered, or sometimes bring up a problem we didn't finish from last class. It's such a broad question that anything would answer it: the main lesson, the smaller steps, a specific equation, a problem everyone was confused on. Many students would think it would be irrelevant in the moment. It's only for 5-10 minutes then we'll move on to today's lesson. However, by asking this, this would refresh everyone's mind and bring them back into the momentum of the class. Typically, the teacher would transition from that question into finishing the last problem or summarizing the last period and begin the next lesson.
When we start getting into the groove of things, another (and I'm sure popular) question teachers have often asked, is,
"Can you explain how you got that answer?"
This is usually asked in a math class. I remember the teacher calling up a couple of volunteers to write their answer and steps on the boards around the room. Then, one-by-one, the student will explain their thought process. This allows for monitoring, and sometimes selecting, specific students with different approaches. Like the problem we did in class about the caterpillars, there is a variety of ways to get to one answer. This also allows for the remaining students to get an idea of how to answer a problem if they were struggling before.