Here are suitable structures to complete the conversations:

### Conversation 1
A: Do you like to study online? And why?
B: Yes, because it’s flexible. You can learn whenever and wherever you like. But I **need to** study online, you must have basic computer skills and be able to manage your time well. How about you?
A: Actually, I don’t enjoy it a lot **because** it lacks real-life interaction. But now the COVID-19 pandemic makes it difficult to come to school, **so** taking an online course seems reasonable.

### Conversation 2
A: Do you like studying in a classroom?
B: Yes, of course because I find it easier to stay focused when I’m in a class. When it comes to online learning, I easily get distracted.
A: I prefer online learning **because** it is flexible and convenient and I don’t have to travel back and forth.

### Conversation 3
A: I don’t like online learning. I’m not good at technology and always run into problems. That’s why I prefer having offline classes where I can have face-to-face interaction with my friends.
B: **I understand what you mean.** I don’t feel the bonding between my teacher and me when I study online.
A: And how about learning with an app? I love it! I feel like playing games but actually I’m learning something.
B: **On the contrary,** I don’t enjoy studying with apps. When I find something difficult to understand, there’s no one around to ask!