Well there alot of challenges faced by biologist researchers during the research of infectious disease, however major of those include the followings:
1- Defining and measuring the fitness for pathogens across the scales
2- Developing models to capture the impact of co-infection on the evolutionary process
3- Modeling how pathogen characteristics shape the evolution of hose immune diversity
4- Understanding the maintenance of pathogen diversity
5- Developing the better models for the impact of genetic systems on pathogen evolution .
1,665 is your answer because 19x19=q qx14=a
Answer: A. Inner Core
Explanation: The inner core is solid, the outer core is liquid, and the mantle is solid/ plastic. This is due to the relative melting points of the different layers (nickel - iron core, silicate crust and mantle) and the increase in temperature and pressure as depth increases. Hope this helps :) If not, I am sorry :( If it does, Your Welcome!
