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.