When trying to distinguish between an infectious disease and noninfectious disease, what is the hallmark symptom for most infectious diseases?

Why do oceanic plates tend to subduction when colliding with a continental plate

Adistinctive characteristic of mammals that is not observed in other vertebrates is

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food