单选题 It's most important to wash your hands frequently and well - 20 seconds with soap and water -and avoid touching your eyes and nose. Alcohol - based hand gels are also effective. Second, to avoid spreading germs, cover your mouth when you cough or sneeze, preferably using your sleeve or a tissue. And third, if you're sick or your child is sick, stay home until the fever has gone away for at least 24 hours without the use of fever - reducing medication.
People can avoid spreading germs by

• A. washing hands frequently and well.
• B. covering mouth when they cough or sneeze.
• C. staying away from the population.
• D. avoid touching eyes and nose after hand washin