At the core of biology and other sciences lies a problem-solving approach called the scientific method. 1  Make an observation. 2  Ask a question. 3  Form a hypothesis, or testable explanation. 4  Make a prediction based on the hypothesis.  Test the prediction.
Xi. Xi is the 14th letter of the Greek alphabet. It is pronounced in Modern Greek, and generally or in English. In the system of Greek numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh. Xi is not to be confused with the letter chi, which gave its form to the Latin letter X.
As the general secretary (de facto leader), Xi is also an ex-officio member of the Politburo Standing Committee, China's top decision-making body. The son of Communist veteran Xi Zhongxun, Xi Jinping rose through the ranks politically in China's coastal provinces. Xi served as the Governor of Fujian, from 1999 to 2002, and then as the Governor and the Party Committee Secretary of the neighboring Zhejiang, from 2002 to 2007.