听力原文： Top public health experts are sounding a warning about the possibility of a bird flu pandemic. The dangerous avian flu virus has infected birds from East Asia to Europe. Human infections have been relatively rare so far --117 cases, according to the World Health Organization, all of whom appear to have gotten the disease from direct contact with birds. Dr. Greg Poland of the Mayo Clinic says two of the three conditions are in place for a global flu epidemic, or pandemic. We already have a new virus for which we don't have immunity ... and the virus can sicken humans.' The remaining condition is for this virus to develop the ability to be easily transmitted from one human to another to another. When this happens, time will be described for those left living as 'before' and 'after' the pandemic.' Which one is not true according to the news?