During the summer you should be even more careful than usual of the foods you prepare. Foods spoil faster in hot weather than in cold weather. When you are shopping, purchase frozen and refrigerated foods, don’t make long stops on your way home because frozen foods could become soft or warm. Using insulated (密封的) bags helps keep food cold until you arrive home. Mild or milk products should be refrigerated immediately. When camping or picnicking or at any time when refrigeration isn’t available, use special dry foods. Above all , if a food doesn’t seem to be normal in odor(气味) or appearance, discard (抛弃) it immediately. Don’t taste it.

What is the main idea of the passage?

A How to store frozen and refrigerated foods

B How to keep food from spoiling (变坏) during the summer?

C How to select fresh food?

D How to prepare summer food

Key:B