Which discourse marker fits best into the sentences?

1. Yes, there is a lot of work to do. , I must rush now, I’ll call you tomorrow.
2. There are two reasons why I think he’s wrong . People don’t act like that, and Paul would certainly never act like that.
3. , I want you to pay attention, everyone.
4. He loses his temper very quickly. He’s got a great sense of humour.
5. You seem a bit sad today. Let me buy lunch for you to cheer you up.
6. A: So I’ll pick you up at 6.30. B: . See you then.