This cools the inner pot and helps keep food safe from harmful bacteria.

VOA: special.2009.02.09

What did you learn about how easy or hard it is to keep track of what food intake is?

你从记录食物摄入过程中,学到了什么,记录饮食是难是易

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

But another way to keep food fresh is to use an evaporative cooler.

VOA: special.2009.11.30

Spices have long been used to keep food safe to eat.

VOA: special.2010.06.01

They would put out sacrifices of food and light fires to keep the spirits from doing any harm to the living.

VOA: special.2010.10.29

Food and guns were difficult to find to keep the Confederate armies in the field.

VOA: special.2009.10.22

"About 85 percent of the average family income is now being used just to buy food to keep a family going."

VOA: standard.2009.09.13

The interrogators were told they could put them in painful standing positions, deprive them of solid food, keep them awake for extended periods of time, lock them in cold rooms, and submit them to the technique of simulated drowning known as waterboarding.

VOA: standard.2009.04.17