variations

In an English auction (also called an Open-outcry auction), the auctioneer begins the auction with the reserve price (lowest acceptable price) and then takes larger and larger bids from the customers until no one will increase the bid. The item is then sold to the highest bidder.

Nubian wedding with some international modern touches, near Aswan, Egypt

The type, functions, and characteristics of marriage vary from culture to culture, and can change over time.

Two millennia of mean surface temperatures according to different reconstructions, each smoothed on a decadal scale. The unsmoothed, annual value for 2004 is also plotted for reference.

Music education comprises the application of education methods in teaching music.

Weather is the day-to-day state of the atmosphere, and is a chaotic non-linear dynamical system. On the other hand, climate — the average state of weather — is fairly stable and predictable. Climate includes the average temperature, amount of precipitation, days of sunlight, and other variables that might be measured at any given site. However, there are also changes within the Earth's environment that can affect the climate.