A: What's the weather like?
B: I don't know. I just woke up.
A: Why don't you look outside?
B: Okay. It looks like rain.
A: Why do you say that?
B: The sky is gray.
A: Is it raining right now?
B: No.
A: How do you know?
B: The street isn't wet.
A: I have to go shopping today.
B: You'd better take an umbrella.