According to Mayo Clinic, Down syndrome causes a distinct facial appearance, intellectual disability, developmental delays, and may be associated with thyroid or heart disease in a person. So calling people with this syndrome 'Mongoloid' is extremely vulgar and disrespectful to ethnic Mongolians. Likewise, how will the population react if Down Syndrome was associated with 'European' looks? If you use this term, you are automatically a xenophobic, in my opinion.
An ERA is a long period of history with distinct characteristics. For example, the roman era. A PERIOD is less distinct and defined, it simply represents a portion of time, be it a very short portion, or a very long portion. For example, my period of sadness and the jurassic period. An EON is an actual unit of time. 1 eon = 1 billion years. This is also used rhetorically to symbolize a long long time. For example, man! my new iphone took like an eon to arrive in the mail! or also more appropriately the earth is 4.5 eons old.
Difference between Weather and Climate. Key Difference: Weather is the state or conditions of the atmosphere over a short period of time, usually a day or so. Climate is the average conditions that are expected at a certain place over a number of years. Weather and climate are words that are often heard in meteorology, while weather is also used in day to day in order to refer to the conditions outside. Weather and climate are similar, but different. The main difference between the two is weather changes day to day, while climate does not change for longer periods of day. Weather is the state or conditions of the atmosphere over a short period of time, usually a day or so.