sentences: companies irradiate some fruits and vegetables & irradiating food can be used to kill existing microorganisms in the food ->  companies irradiate some fruits and vegetables to kill existing microorganisms in the food  companies irradiate some fruits and vegetables to kill existing microorganisms in the food & killing microorganisms in food can be used to extend the shelf life of that food -> companies irradiate some fruit and vegetables to extend the shelf life of that food