Why do vaccine makers have to guess which flu strains will be active months before the flu season begins?

Which literary device has emily dickinson used in these lines? how dreary to be somebody! how public, like a frog to tell your name the livelong day to an admiring bog! metaphor alliteration simile allusion

What is the best way to revise sentence number (12)

What is the main idea of this paragraph from the volcanoes section of the ready.gov website