Repeat A: What is that black goo you're carrying? B: It's roofing tar. A: Are you replacing your shingles? B: Yes I am. The roof has been leaking in the rain. A: Isn't tar very messy? B: Yes, I need to be careful with it. A: How long does it take to finish? B: It takes several hours to replace all the shingles. A: I think you'd better work very quickly. B: Why do I have to work quickly? A: It looks like it's going to rain again tonight. B: Sometimes I think Mother Nature just likes being mean.