Please choose the correct ending to complete the given sentence: Health: [header] How to fight pandemic flu [title] Cover your mouth and nose when you cough or sneeze. [step] One way to help prevent pandemic flu, or fight it if it ever occurs, is to cover your mouth when you cough and your nose when you sneeze. Viruses, including the influenza virus, easily pass from person to person through the air.

Ending1: Simply covering your nose and nose when you cough can help to prevent the spread of the virus to others. [substeps] Put your hand over your nose and mouth when you cough or sneeze. Ending2: [substeps] Cough or sneeze into a tissue if at all possible. If you don't have a tissue, cough or sneeze into your arm instead of your hand. Ending3: Keeping the fine details of your mouth closed makes it less likely that the flu virus will enter your airways. [substeps] Also, make sure you cover your mouth and nose. Ending4: Coughing and sneezing can help protect your open airways and prevent the spread of pandemic flu. [substeps] Cover your mouth and nose when you cough or sneeze.

Answer format: ending1/ending2/ending3/ending4