A、Play jokes on others. B、Say "April Fool" to others. C、Celebrate the New Year. D、Celebrate the adoption of calendar. C

April Fool’s Day started in the sixteenth century in Europe. Before that time, New Year’s Day was celebrated on April 1st. Then a new calendar was introduced called the Gregorian calendar. January 1st became the first day of the year, but many people did not know about it. So those who continued to celebrate New Year’s Day on April 1st were laughed at. They were called fools.
    Nowadays we play jokes on people on April 1st. For example, someone might put salt in the sugar container so another person could "accidentally" put it in their coffee. Or someone might change the time on another person’s alarm clock so that person would unknowingly wake up earlier or later than planned. Or maybe a person would tell a lie to make someone else shocked. After we play the trick, we say "April Fool." Then the poor person realizes he was fooled. In many countries newspapers and the other media participate with false headlines or news stories. It is generally done in the spirit of fun and doesn’t cause any real harm to anyone. Do you have any great jokes to play on others? Try it out an April 1st. Just don’t forget to say "April Fool" when the other person begins looking a little confused.