【简答题】The formation of "flu" from influenza is a front and back _____________.
【简答题】在 CSS 中,用于设置行间距的属性是【】,一般称为行高
【单选题】People who care for those most vulnerable to the influenza infection needn't get flu shots.
【单选题】According to CDC, birds carry every known subtype of influenza A and can transmit the flu directly to humans.
【单选题】The word flu which comes from influenza is created through______.
【单选题】Flu is a contagious respiratory illness caused by influenza viruses that infect .