食品保质期
CBS News: experts say consumers often get confused by date labeling on food products, and end up either keeping spoiled food around too long, or throwing away perfectly good food unnecessarily -- costing us billions of dollars.
In new a survey by the public health and safety organization NSF International, researchers found that people have trouble understanding and differentiating between common food label terms such as "expiration date," "best if used by date" and "sell by date."
Consequently, almost half of Americans do not throw away food until they see mold or color changes. And 17 percent of Americans say they just toss food when it starts to smell.
1 perfectly
adv.完美地，无可非议地，彻底地
参考例句：
The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。
2 differentiating
[计] 微分的
参考例句：
They succeed in differentiating the most commodity-like products. 在最通用的日用产品方面，它们也能独树一帜标新立异。
The simplest and most effective method of differentiating areas is to use different colours. 区别面状要素最简单而又行之有效的办法，是使用不同的颜色。
3 expiration
n.终结，期满，呼气，呼出物
参考例句：
Can I have your credit card number followed by the expiration date?能告诉我你的信用卡号码和它的到期日吗?
This contract shall be terminated on the expiration date.劳动合同期满，即行终止。
