B: I don't feel well these days, and my stomach is upset.

You must not finish breakfast every morning.

Actually, I'm too busy to finish breakfast. I think eating breakfast is a waste of time!

A: If you don't eat breakfast, you will feel weak, and then you won't have enough energy to finish your work. That's why you feel so bad these days.

B: Well, I'll be careful in the future. Thank you.