Plzz with this question its science

The influenza virus cause the flu, but not other diseases. why?

Need an answer asap 45 points and brainlest to the first person to answer why do scientific theories, such as biological and chemical evolution, represent the strongest explanation of the changes observed in the fossil record. must be in sentence form how can scientific theories on evolution and the fossil record change over time? must be in sentence form

What are the student's observations and inferences before he starts his investigation?