Water is necessary for life and good health. We often forget this fact when we think about the other building blocks of life, su

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问题    Water is necessary for life and good health. We often forget this fact when we think about the other building blocks of life, such as vitamins, minerals and proteins. We can live for many days without eating. However, only two or three days without water usually leads to death.
   The human body may look solid, but most of it is water. New-born babies are as much as eighty-five percent water. Women are about sixty five percent water, and men about seventy-five percent. Women usually have less water than men because women, in general, have more fat cells. Fat cells hold less water than other kinds of cells.
   Water is necessary for cooling the body on hot days, and when we are working hard or exercising. Water carries body heat to the surface of the skin when the heat is lost through perspiration.
   Researchers note that fat cells block body heat from escaping quickly. Fat cells under the skin act like warm clothing to keep body heat inside. This is why over-weight people have a more difficult time staying cool than thin people.
   Researchers also note that cold liquids cool us faster than warm liquids. This is because cold liquids take up more heat inside the body and carry it away faster. They say, however, that cold sweet drinks do not work well. The sugar slows the liquid from getting into the bloodstream.
   The body loses water every day through perspiration and urine. If we lose too much, we will become sick. To replace what is lost, health experts say grown persons should drink about two liters of liquids each day, and more in hot weather. They say we also can get some of the water we need in the foods we eat. Most fruits and vegetables have more than eighty percent water. Even bread has about thirty-three percent water.
What should we do to keep enough water in the body?

选项 A、To take two liters of water daily all through the year.
B、To eat everything that contains water.
C、To take in as much as we have lost.
D、To drink only when we feel very thirsty.

答案C

解析
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