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.
Report Abuse. 1  Growing up around Baltimore and DC in the 70's and 80's, a lot of sex shows were triple XXX rated on the adverstisments. 2  Xxx Emoticons. 3  xxx = kisses.  what does xxxxx mean at end of a 1  letter. it mean i love 2  ya. xxx means hugs and xoxo means hugs and kisses.