2020 is a leap year!
Superman has a birthday this year. Superman and anyone else born on February 29 only get the day of their birth every four years, in a leap year (闰年). On this year’s calendar, February 29 is there!
It’s because the calendar the world uses is based on the time it takes for the Earth to orbit (绕……运转) the Sun. But the Earth doesn’t orbit the Sun in exactly 365 days. In fact, it takes 365 days and about one quarter of one day for the Earth to complete its full orbit.
The calendar manages this by making the regular year 365 days, and every fourth year — called a leap year — we get an extra day, called a leap day. Leap years have 366 days. Non-leap years are called common years.
The internationally accepted calendar is called the Gregorian calendar. It’s also known as the Western or Christian calendar. It is named after the Catholic Pope (天主教教皇) Gregory ⅩⅢ, who introduced it in 1582.
The rule for leap years is: every year that can be divided by four is a leap year, except for years that can be divided by 100, but these centurial (一世纪的) years are leap years if they can be divided by 400.
So 1700, 1800 and 1900 were not leap years. The years 1600 and 2000 were leap years and 2400 will also be.
manage /'m?n?d?/ v. 完成（困难的事）；应付（困难局面）
eg. I managed to get out at the right station.
extra /'ekstr?/ adj. 额外的；附加的
eg. The bus company provided extra buses because there were so many people.
divide /d?'va?d/ v. 除
10 divided by 2 is 5.
* Our 1. ______ is based on the time it takes for the Earth to orbit the Sun.
* It needs 365 days and about one quarter of one day to complete its full orbit.
* To deal with this problem, the calendar adds an extra day every 2. ______ years.
* Every year that can be divided by four is a leap year, except for years that can be divided by 100.
* Centurial years that can be divided by 3. ______ are leap years.
1. calendar 2. four 3. 400