The flu can be serious among the elderly or .
举一反三
- It has been discovered that______. A: H5N1 does not transmit among human beings B: bird flu spreads only among birds C: H5N1 is a variant of flu virus D: bird flu adapts easily to other species
- It is these poisonous products _______ can cause the symptom of the flu, such as headache and aching muscles.
- (1) Obesity is a serious health problem, and the prevalence of obesity continues to increase among adults in the US.
- Avian flu can be prevented in affected areas by taking some precautionary measures.
- Which of the following can be seen as the most serious fiction?