I think she likes me because she was stuck in my lab group and we were talking before and my teacher told everyone to give their cell numbers out to the people in their lab group. I didn't expect our talking to get very far but when I get home I check my texts and she said hey and we talked a little. When I see her tomorrow in class what do I say to keep the conversation rolling?

Since it's the just the start of the semester, I would say to just relax, and play it cool. don't get one-itis with this girl. Crack jokes with her, kino her a little when you can (and not creep her out) and lead her to want to get to know you.

I have encountered this problem twice already, and blown it twice, lol. The key, I've learned, is to stay high energy/friendly without being needy. Make sure to give everyone around you more attention than her. Then, once the classroom has settled down, pass her notes that say, "you know, this isn't an ASL class. You can talk to me more," or, "hey, so doesn't our teacher (enter weird tick about the instructor)." Be playful and upbeat. Don't be, "Mr. Serious who wants to focus on getting a good grade." She will HATE THIS. Talk to her about your day, tell her stories, spout game. It doesn't matter, just keep the conversation going. However, it's ok to not say anything if the teacher is lecturing. She will understand that you are focused on learning, but you don't mind having fun either. Good luck bro.