题目内容：

    You can tell a lot about a country by what's on its television sets. Britain's TV screens are completely steeped in class, and have long been so.

From laughing at poor people in reality shows to laughing at posh people in Downton Abbey, this is how Britain likes to unwind in the evening: by laughing at other classes, and laughing at people for laughing about class.

Like it or loathe it, many see the class system as a quite essential element of British life, together with our obsession for tea and cake and talking about the weather.

Whether you are a lord, a lady, or just the king of your own middle class  kingdom, everyone in the UK fits into the class system. How the class system works is a hard question even for a British person to answer.

There are four main groups in the British class system: lower, working, middle and upper class. Although recently the BBC has tried to confuse everyone even more by adding three more categories.

The British are very aware of class; it is often said that we have an in-built 'class radar'; we pick up on subtle social clues which indicate which class a person comes from. Class is not just about your job, where you live and how much you earn. It's about who you are.

1.According to the passage ,what Britain are not likely to talk about?

A. Weather B. Class

C. Jokes D. Tea and cake

2.How many class categories are there according to BBC?

A. Five B. Three

C. Seven D. Four

3.Why Britain are so obsessed with class?

A. Because many see the class system as a typical part of British life.

B. Because class is about who you are.

C. Because how the class system works is a hard question even for a British person to answer.

D. Because there are different groups in the British class system.