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.