What did Jack do over the summer?

W: Hi, Jack. How was your vacation?
M: Hey, Sunny. It was pretty good. I had to study a lot, though.
W: Why? Did your teachers give you a lot of summer homework?
M: No, it’s not that. Ms Wellington is going to be one of my teachers this year.
W: I’ve never been in her class. Is she tough?
M: Tough? She’s one of the hardest teachers in school.
W: How do you know ?
M: I had one of her classes last year. She gave us so much work that it was really hard to get it all done.
W: So were you studying over the vacation to get a head start?
M: That’s exactly right. I just hope I did enough.