For you,the “Clear and Bright” day that falls in every April might be no more than just another holiday — the fact that it comes with three days off school matters to most students       1       more than the fact that it is part of the 24 solar terms.

But the UNESCO has recognized the importance of the 24 solar terms. This ancient system that Chinese people have used to keep track of the time of year       2     (add) to the UNESCO list of Intangible Cultural Heritage of Humanity on Nov 30.

For starters, you may have heard your mom say: “The sanfu days are almost over. The heat won’t be here for long.” The sanfu days are a period of time that     3     (fall) in summer, somewhere     4     Minor Heat (in July) and Autumn Equinox (in September). The coldest days, or the sanjiu days, are similar. They cover the 27 days     5     (follow) Winter Solstice.

In some places, solar terms guide people’s lives through special foods,     6     (culture) events and healthy living tips. For example, people from northern China are in the habit of eating dumplings on the day of Winter Solstice. And on Start of Autumn, some people treat     7     to a big feast, especially of meat, something they call “putting on autumn weight”, or tieqiubiao.

But no matter     8     differently people celebrate the 24 solar terms, they have been here for a long time and could last forever.

According to Chinese writer and academic Yu Shicun, unlike many other examples of intangible cultural heritage – Peking Opera and Chinese Zhusuan, for example – the solar terms are neither regional (地域的) nor a type of art or skill. Instead, the system is a philosophy of time,     9     applies to everything. And this means they are     10     (likely) to die out.

There is a common fear of the number 13. It’s a number just like any other,     1     there are horror movies about it; some buildings     2     (intention) have no I3th floor; and plenty of couple avoid gating married on the13th of the month.

What makes this number so scary? Historians have pointed a few potential     3     (reason) about the origin of this fear, the most popular of which is that there were 13 diners at the Last Supper. The 13th lo arrive was Judas,       4     betrayed Jesus.

Actually, there are no problems with the number     5     (it). Maybe 13 is next to the number 12, and that makes it look bad. In many ancient cultures, 12     6     (consider) to be a perfect number. Most ancient civilizations based their systems of telling time around the number 12, There are 12 hours on a clock, and 12 months in a year. Twelve is also     7     largest number that also has one syllable (音节) in English. As the number immediately following this “perfect” one, 13 seemed imperfect,     8    (inspire) unease throughout the ancient world.

So far, both myth and math     9     (combine) to make this particular number scarier than any other. The uneasiness about the number,     10     ( date) bark to ancient times, has been developed over the years.