Read the passage. April Fools' Days Around the Worla
April Fools' Day is celebrated around the world, although it varies somewhat from country
to country. In the United States, for example, it's a day to play practical jokes. In France,
where the holiday is known as Poisson d'Avril, or April Fish, people secretly tape paper
fish on their friends' backs. A common April Fools' prank in Portugal is to throw flour on
someone; in Scotland, the most popular trick involves sending someone on a useless
errand, Denmark celebrates April Fools' Day on April 1, but some people there celebrate
again in May. Maj-kat, on May 1, yet another day for jokes and pranks in the spring.
What is the main idea of the passage?