A、A customer has to tip the waitress. B、A customer has to pay each time he gets drinks. C、A customer has to pay for all the drin

Tom: Kelvin, could you tell me something about the bars? I have never been to a bar. You see, Steve, my classmate has invited me to go to a bar tonight.
Kelvin: I see. You know, the word "bar" means a room in a pub. We say the bar when we mean the part of that room where drinks are kept. Soon after you go into the pub, you’ll realize that nobody comes to the tables to take orders or money, instead, customers go to the bar to buy their drinks.
Tom: I see. People will go to the bar directly to get their drinks and don’t wait for someone to come to take their orders.
Kelvin: That’s right. People don’t queue at the bar, but they do wait till it’s their turn.
Tom: Oh, how do I pay? I mean do I pay directly after I get the drink or do I have to wait till I am ready to leave like I do in a restaurant?
Kelvin: It’s not the custom to pay for all your drinks when you’re ready to leave, instead you pay at the bar each time you get drinks. It helps if you’re ready to pay as soon as you’re served, and you’ll notice that many people wait with their money in their hands.
Tom: I see. Do I have to give a tip?
Kelvin: No. It’s not the custom to give a tip. It’s very common for friends to buy their drinks together in rounds. This means that each person takes a turn to buy drinks for everybody in the group. It’s faster and easier, both for you and for the person serving if drinks are bought in this way. Naturally you don’t have to have a drink in each round if you don’t want one.
Tom: That’s interesting.
Kelvin: When you’re looking for somewhere to sit, remember that people have to leave their seats to get drinks, etc., so an empty seat may not in fact be available to use. If you’re not sure whether a seat is free, ask someone sitting near if. When it’s time for another drink, people usually take their glasses back to the bar to be filled again. If you’re leaving, the friendly thing to do is to take your glasses back to the bar, thank the person who’s been serving you, and say "goodbye" or "goodnight".
Tom: Thank you, Kelvin. This helps me a lot. By the way, what kind of drinks are available in pubs? Kelvin, Well, you can get both alcoholic and non-alcoholic. Besides alcoholic drinks such as beer and wine, there is cider, which is made from apples, usually sold in bottles, port—a type of thick, sweet wine from Portugal, sherry, which is a type of wine from Spain, and spirits—these are a kind of strong alcoholic drinks such as whisky and brandy.
Tom: What about non-alcoholic? I don’t drink alcohol.
Kelvin: Well, they offer all kinds of fruit juices, such as orange and tomato. These drinks are usually sold in small bottles. And soft drinks,’ we often call sweet drinks, like Coke and Fanta. They are normally sold in small bottles or cans. And lemonade, which is a clear and sweet drink made with carbonated water. They also serve cordials.
Tom: What are cordials?
Kelvin: Cordials are strong and sweet drinks tasting of fruit, such as lime cordial, black-currant cordial. ;I’hey are often added to other drinks or drunk with water.
Tom: I don’t like sweet drinks. Are there any other non-alcoholic drinks?
Kelvin: Yes, mineral water, but it’s not available in all pubs.
Tom: Kelvin, one more question. What is VAT? I saw this on most goods in Britain?
Kelvin: Well, VAT stands for Value Added Tax. The price shown on most goods in Britain includes a tax of 15%. If you use the Retail Export Scheme this tax can be returned to you if you take the goods with you when you leave Britain. You may have to spend a certain sum of money before you qualify for the scheme, and you’ 11 have to show your passport. Ask in the shop if they operate the Retail Export Scheme. If they do, the shop assistant will explain how you can get the tax back and fill in a form with you. VAT is also charged on hotel, restaurant bills, theatre, cinema tickets and car hire.
Tom: Are these refundable?
Kelvin: No, it’s not refundable in these cases.
Tom: Thank you very much. I really learned a lot.