单选题 The loss of perishable goods in transit means lost revenue. However, a number of technologies and new solutions can take the fear out of shipping perishable goods such as seafood products and meat. A team of scientists has developed a color indicating label, which ______ the freshness of meat and seafood products.
This battery-powered label uses a special sensor which includes chemical materials ______ to the inside of the plastic wrap. This reacts with the gas levels in the package, which changes depending on the freshness of the food.
The freshness of the food inside can ______ without opening the food package by using special sensors that look like bar-code reader.