Part 2: Read the text below and choose the best answers

The main element required for survival are food, fire, shelter and water. Their order of importance will depend upon where you happen to be. In the desert, water will head the list. Water is the most common liquid on Earth. It covers about 71. 4% of the Earth. Pure water has no smell, taste, or color. Water is the main component of drinks like milk, juice, and wine. Water is very important for life but it is something that most people in the modern world take for granted. They are so used to turning on a tap that until an extreme drought causes water rationing they seldom think about it. Yet the survivor at sea, or after a flood, though surrounded by water, may be desperate for drinkable water. And there are many places where, unless it rains, no obvious water is available. Although there could be other survival necessities to deal with, water is always universally important.

The factor which decides the order of importance for the main elements required for survival is______.