TASK DEFINITION: You are given a sentence from a conversation between a human and a virtual assistant. Your task is to identify whether the sentence is a question or not. Answer with Yes or No.
PROBLEM: That's right. Do they serve alcohol? And how expensive is the place?

SOLUTION: Yes

PROBLEM: Which city are you looking for? And what time?

SOLUTION: Yes

PROBLEM: They're prices are moderate.

SOLUTION:
No