题目内容：

You probably laugh at something you find funny, but how much do you really know about jokes and humour? Reader's Digest (RD) questioned several experts to give us some facts about them.

RD: What’s the oldest joke in the world?

“We can't know the oldest joke in the world because it would have existed earlier than writing,” says Christie Davies, professor of sociology at the University of Reading in the UK. The oldest joke book that's been found so far is the Greek Philogelos. It dates from the 4th century AD, although the jokes date from an earlier time. According to psychologist Steve Wilson, director of National Humor Month (April in the US), it contains 265 jokes.

RD: Do some people fail to develop a sense of humour?

Rod Martin, professor of psychology at the Western University in Canada, believes that while everyone is born without a sense of humour, as we develop, humour and laughter begin to appear. “Of course, some children are more serious, quiet, and less likely to laugh frequently, but this doesn't mean they don't have a sense of humour.” And according to Steve Wilson, there are no adults who don't have a sense of humour. “Almost everyone is able to develop a sense of humour, and I teach people how,” he says.

RD: Do people share a sense of humour unique to their own nation?

Sense of humour does differ a lot by country, according to an author named Scott Weems. British humour is thought to be absurd (荒谬的) in nature, while American humour has an aggressive quality. According to a study, Germans are found to find everything funny.

1.What do we know about the oldest joke book?

A. It remains unknown.    B. It was written in Greek.

C. It was found in the UK.    D. It contains the oldest joke.

2.What does Rod Martin agree with about people's sense of humour?

A. Nobody is born with a sense of humour.

B. Some adults lose it when they grow up.

C. Childhood is the best time to develop such ability.

D. Children have a poorer sense of humour than adults.

3.What kind of humour has an aggressive feature?

A. British humour.    B. German humour.

C. Canadian humour.    D. American humour.

4.Where can you probably find the text?

A. In a popular magazine.    B. In a research paper.

C. In a personal diary.    D. In a textbook.