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Solar terms, also called Jieqi in Chinese, are days marking one of the 24 time buckets or the solar year in traditional Chinese calendar and【小题1】(use) to indicate the alternation of seasons and climate changes in ancient China.

The Yellow River Basin in Northern China is believed to be the cradle of the solar terms system. China's 24 solar terms are 【小题2】 knowledge system and social practice formed through 【小题3】 (observe) of the sun's annual motion and cognition of the year's changes in season, climate and phenology(物候学). Ancient Chinese divided the sun's movement through the sky 【小题4】 24 segments(时间段), with each segment equaling one 【小题5】 (rough) two-week-long "solar term". 【小题6】 (base) on the sun's position in the zodiac, the 24 solar terms were created by farmers in ancient China to guide the 【小题7】 (agriculture) affairs and farming activities. They serve as an instruction   manual of sorts for farmers, 【小题8】 (allow) them to know 【小题9】 conditions to expect or what agricultural activities to carry out during certain periods of the year.

Solar terms are often called China's " 【小题10】 (five) great invention " after paper making, printing, gunpowder and the compass.