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.
Xiamen (å¦é¨; XiÃ mÃ©n) is a coastal city in Fujian Province in China. It has been an important port for centuries and became one of China's earliest Special Economic Zones in the 1980s. The name Xiamen means door to the house, referring to the city's centuries-old role as a gateway to China.