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3. History of the Solar Calendar A Solar Calendar ...
3. History of the Solar Calendar A Solar Calendar is a way of measuring and recording periods of time.It takes for the Earth to revolve around the Sun. With the help of the solar calendar, we can predict the times in which the sun will set and rise every day throughout the course of the year as well as the occurence of Solar and Lunar Eclipses when it is compared to the Lunar Calendar. The solar calendar was first developed by the Egyptians who used the annual appearance of the Dog Star-Sirius , which coincided with the yearly flooding of the Nile River, as a fixed point. However, the Egyptians forgot to consider the extra fraction of a day in their 365 day calendar. Later, the Roman republic calendar, based on the Lunar Calendar of the ancient Greeks, was replaced by Julius Caesar in favour of the Julian Calendar. The Julian Calendar allowed for February’s leap year but made the solar year too long by adding a quarter of a day annually. By the 16th Century, the extra time accumulated to form an error of around 10 days which was corrected in the form of the current Gregorian Calendar. In the Western World, the definition of the year is based on the Earth’s revolution around the Sun and, therefore, is referred to as a “Solar Year”. However, several varieties of Solar years exist: A Tropical Year lasts 365.242199 days UT and the name refers to the changes of seasons (from the greek ‘tropai’ meaning “the turning points”) which are fixed in this kind of year. A Sidereal Year lasts 365.256366 days UT and is the interval between two successive passages of the Mean Sun at the same star. What is the difference between a Lunar and Solar Calendar？ There are 365 days in a solar calendar year and an additional day during leap years. In a Lunar calendar, there are 354 days and 384 in a leap year. A Lunar Calendar will shift very quickly in contrast to a solar calendar. 6. What is the difference between a Lunar and Solar Calendar？
A、There are 365 days in a solar calendar year.
B、In a Lunar calendar, there are 384 days.
C、A solar calendar will shift very quickly.
D、There is an additional day during solar year.
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式中：T≥0为时滞常数。在Matlab中提供了命令dde23来直接求解时滞微分方程。其调用格式为801=dde23(ddefun，lags，history，tspan，options)，
已知，在i≤0时，x(t)=5，x2(t)=0，x(1)=1，试求该方程组在[0，40]上的数值解。
（二选一作答即可） 一、在钢琴或一切有声音的键盘上弹奏出考试曲谱。答案以录制视频形式上传至附件。 二、在乐谱上为每个音符标写指法和唱名，指法用1、2、3、4、5表示，唱名用do、re、mi、fa、sol、la、si表示。每个音符都需要标记。答案以图片形式上传。
