Final answer:
The formal language in the passage emphasizes the significance and urgency of the information about preventing avian flu transmission from birds to humans.
Step-by-step explanation:
The formal language used in the passage adds a level of seriousness and direction to the text, which aims to address the concerns over the transmission of the avian flu to humans. This usage of formal language emphasizes the grave nature of zoonotic diseases, thereby stressing the significance of the information being conveyed. It is not used to create agencies, influence any one person, or persuade an organization to take action directly. Instead, it is meant to underscore the importance and urgency of the research and information related to preventing the spread of diseases like avian flu from birds to humans.