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.