On the line before each item, identify each word group in the following paragraph as a sentence fragment*(F)*, a run-on sentence (R), or a complete sentence(S).
Example:[1] R Time is a relatively new human concept before people began farming, they had no need to keep track of passing days.
[2] F Watching day turn into night and winter turn into spring.
_______ [1]Humans first developed calendars in the early river-valley civilizations these river valley were the Nile, Tigris, and Euphrates, Indus, a Huang He ______ [2] Farmers had to know when to plant crops, sometimes the farmers even needed to predict the arrival of yearly floods. ________[3] Most early calendars based on lunar months, the amount of time between each full mom. ____________ [4] A problem with using lunar months is that the calendar would fall short of a full year, each year the months would come earlier until the calendar would fall short of a full year, each year the months would come earlier until the calendar would no longer be useful. _______[5] Many cultures solving the issue by adding extra days to the calendar. ______________ [6] Feasts and holidays, for example, on the five extra days of the ancient Egyptian calendar. [7] Since the popularity of the Chinese rules of the Shang dynasty depended on the accuracy of their astronomer's calendar, the astronomers were very important. [8] The astronomers also predicted eclipses of the moon with great skill an error of twenty-four hours caused outrage and alarm. _______[9] Today, official atomic clocks measuring the vibrations of electrons in cesium atoms. _____[10] These atomic clocks are so precise that they have to adjusted to make up of the slowing in the earth's rotation scientists occasionally have to add leap seconds on New Year's Eve!