Nitrogen gas reacts with hydrogen gas to form ammonia. what are the reactants in this chemical reactions

The formula for this reaction would be

N + H3 ---> NH3

The first part of the reaction are the reactants and the second part is the product.

The reactants of this reaction are N and H3.

Or you could say the reactants are nitrogen and hydrogen

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

answer; polycythemia is the correct answer;