One in three UK consumers throw away food just because it reaches the use-by date (使用期限), but 60% of the food we throw away each year is safe to eat.

In order to help detect spoilage (变质) and reduce food waste for supermarkets and consumers, researchers have developed spoilage sensors for meat and fish packaging. The researchers say the sensors could also finally replace the use-by date — a widely used indicator of being fresh and eatable.

The sensors cost two US cents each to make. Known as “paper-based electrical gas sensors (PEGS)”, they detect spoilage gases in meat and fish products. The information provided by the electronic nose is received by a smartphone, and then you can know whether the food is fresh and safe to eat.

The researchers made the sensors by printing carbon electrodes (电极) onto a special type of paper. The materials are eco-friendly and harmless, so they don’t damage the environment and are safe to use in food packaging. The sensors, combined with a tiny electronic system, then inform nearby mobile devices, which identify and understand the data about spoilage gases.

Lead author Dr. Firat Guder of Imperial’s Department of Bioengineering said, “Although they’re designed to keep us safe, use-by dates can lead to eatable food being thrown away. They don’t always reflect its actual freshness. In fact, people often get sick from food-borne diseases due to poor storage, even when an item is within its use-by date. These sensors are cheap enough, so we hope to see supermarkets using them within three years. Our goal is to use PEGS in food packaging to reduce unnecessary food waste.”

【小题1】What is the purpose of PEGS?

A．To test the freshness of food.	B．To make food taste better.
C．To help supermarkets store food.	D．To keep the meat and fish fresh.

【小题2】What can we know about the sensors in paragraph 4?

A．They are made of special paper.	B．They don’t produce pollution.
C．They are built in mobile devices.	D．They directly show people information.

【小题3】What does Dr. Firat Guder say about use-by dates?

A．They are not completely reliable.

B．They determine the freshness of food.

C．They can help reduce food waste.

D．They help prevent food-borne diseases.

【小题4】What is the text mainly about?

A．The process of developing spoilage sensors.

B．A new device in packaging to reduce food waste.

C．The application of spoilage sensors in food processing.

D．Use-by dates’ influence on supermarkets and consumers.