Look ! Someone is celebrating his birthday .
neutral
user
This must be his 21st birthday . No doubt about it .
neutral
assistant
Why ? Do you know that guy ?
neutral
user
No . Well , in America , 21 is the age when you're allowed to drink . So , many guys celebrate it in bars .
neutral
assistant
That's interesting . But it would be really expensive , I suppose . Just think about all the drinks .
neutral
user
No . If it's your birthday , then you don't need to pay a cent . Just blow out the candles and open the gifts . That makes the birthday a special day . Your friends will take care of everything .
neutral
assistant
Wow . That's wonderful .
happiness
user
What about in China ? What'd you do to celebrate your birthday ?
neutral
assistant