DEVELOPMENT REPORT - Simple Ways to Keep Food Cool
DEVELOPMENT REPORT - Simple Ways to Keep Food Cool
By Bob Bowen
Broadcast: Monday, September 05, 2005
I'm Faith Lapidus with the VOA Special English Development Report.
Bacteria 1 can make foods go bad. This is true of cooked foods as well as fresh foods. The problem is especially dangerous when the air around food is warm. High heat kills bacteria. But warm, wet conditions help bacteria grow.
So, the best way to protect food is to keep it in a cool place. There are several ways to keep food cool without the need for electricity. Some refrigerators, for example, are powered by gasoline 2 motors 3.
There are less costly 4 ways than refrigeration to keep food cool. An ice box is a simple device 5. It is made mostly of wood. The inside walls are covered with metal. A big piece of ice is placed in the bottom. Millions of homes had ice boxes until refrigerators became common in the nineteen forties.
An ice box will keep food from spoiling 6 for several days if the outside temperature is not too warm. If the box is kept out of sunlight 7, the ice will last longer.
Probably the best method to keep food cool without electricity is a device called the evaporative cooler. Evaporation 8 is the natural change of water from liquid to gas as the water mixes back into the atmosphere. An evaporative cooler is easy to make. And it does not need ice.
One common evaporative cooler is built as a tall box. Food is kept on several shelves inside. The shelves are made from pieces of metal with many small holes. All four sides of the box are covered with thick cloth. A container of water is placed at the bottom. Another container of water is placed at the top.
The top and bottom of each piece of cloth is placed in the water. This keeps the cloth wet.
Put the cooler out in the open air, but not in the sun. Air will pass through the wet cloth. This keeps the inside of the box several degrees cooler than the outside air temperature. And this is often just cool enough to keep foods fresh.
This VOA Special English Development Report was written by Bob Bowen.
Many of our reports about simple technologies are based on information from the group Volunteers in Technical Assistance 9. Earlier this year, VITA joined with another non-profit group, EnterpriseWorks Worldwide. The combined organization is called EnterpriseWorks/VITA. The Internet address is enterpriseworks.org. I'm Faith Lapidus.
- Bacteria are invisible to the naked eye.细菌是肉眼看不见的。
- The biology of bacteria can be quite hard to understand.细菌生物学有时会很难理解。
- This car runs 5 miles on a gallon of gasoline.这部汽车一加仑汽油可以行驶五英里。
- There is still some gasoline left in the tank.油箱里还剩下一些汽油。
- The United Auto Workers hit the bricks against General Motors. 联合汽车工人工会举行罢工，反对通用汽车公司。 来自《简明英汉词典》
- The whine of the motors jangled her nerves. 马达的闹声使她的神经受不了。 来自《现代英汉综合大词典》
- It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
- This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。
- The device will be in production by the end of the year.该装置将于年底投入生产。
- The device will save much time and effort for us.这种装置会使我们节省大量时间和气力。
- You are spoiling this man's son. 贼夫人之子。 来自《现代汉英综合大词典》
- The murderer attempted to escape from law punishment by spoiling his own face. 那个杀人犯企图自毁容貌以逃脱法律的惩罚。 来自《简明英汉词典》
- The room was flooded with warm and golden sunlight.房间充满着温暖、金色的阳光。
- In the bright sunlight she had to narrow her eyes.在强烈阳光下她必须眯着双眼。
- Be careful not to lose too much liquid by evaporation.小心不要因蒸发失去太多水分。
- Our bodies can sweat,thereby losing heat by evaporation.我们的身体能出汗，由此可以蒸发散热。
- She called and called but no one came to her assistance.她叫了又叫，但没有人来帮。
- He will get the great possible assistance.他将获得尽可能大的帮助。