I am looking for a college in the centre of cambridge
There are several colleges in the center. May I suggest Saint Catharine's College?
OK, that sounds like a good idea. How much does it cost to visit?
The admission is free!
May I have the postcode, please?
Yes, the postcode is cb21rl. Is there any thing else I can help you with?
Yes, I would like an expensive Vietnamese Restaurant in the Centre.
Sorry, I couldn't find any restaurants matching your requirements.
Are there any restaurants that serve italian food in the area?
There are 4 available, can i recommend, stazione restaurant and coffee bar?
Sure that sounds good. I want to book a table for 2 people at 12:45 on Tuesday. 
Reference number is : A4RXHHPX. Is there anything else?
That's all I need, thanks so much for your help! Have a good day!
You too, thanks for calling!