A、People must play jokes on friends on April Fool’s Day. B、Sometimes jokes last until the end of April Fool’s Day. C、People usua

Unlike most of the other holidays, the history of April Fool’s Day is not totally clear. (19)The closest point in time that can be identified as the beginning of this tradition was in 1582, in France. Before that year, the new year was celebrated for eight days, beginning on March 25 and lasting until April 1. With the reform of the calendar under Charles IX, a new calendar was introduced, and New Year’s Day was moved to January 1. However, many people did not receive the news or refused to accept the new calendar and continued to celebrate the new year on April 1. These backward folk were labeled as "fools" by the general public. They were often sent on "fool’s errands" or were made the target of other practical jokes. This evolved, over time, into a tradition of joke-playing on the first day of April. (20)The tradition eventually spread to England and Scotland in the 18th century. It was later introduced to the American colonies of both the English and French. Jokes performed on April Fool’s Day range from the simple (such as saying ’Tour shoe’s untied!"), to the elaborate. Setting a roommate’s alarm clock back an hour is a common trick. Whatever the joke, the trickster usually ends it by yelling to his victim, "April Fool! " Practical jokes are a common practice on April Fool’s Day. (21)Sometimes, elaborate practical jokes are played on friends or relatives that last the entire day. The news media even gets involved. For instance, a British short film once shown on April Fool’s Day was a fairly detailed documentary about "noodle farmers" and how they harvest their crop from the noodle trees. April Fool’s Day is a "for-fun-only" celebration. Nobody is expected to buy gifts or to take their "significant other" out to eat in a fancy restaurant. Nobody gets off work or school. It’s simply a fun little holiday, but a holiday on which one must remain forever alert, for he may be the next April Fool!
19. When was the new year celebrated in France before 1582?
20. When did the tradition of April Fool’s Day spread to England?
21. What do we know from the passage?