How is the concept of friendship portrayed in both Society and Solitude and Chapter I of Nature? Friendship is considered to be preferable to solitude.
Friendship is considered to be valuable but not necessarily vital.
Friendship is considered to be crucial to society.
Friendship is considered to be a worthless relationship.

answer: b (host)

viruses use the cells of living organisms to reproduce. the cell which is used by virus is called as "host cell". it is a living cell in which virus multiplies, example bacteria, plant or an animal cell.

in this, the virus is a parasite, which uses host cell for its benefit (reproduction) by using the cell machinary of host cell.

the answer is industry

basic principle: a pronoun usually refers to something earlier in the text (its antecedent) and must agree in number — singular/plural — with the thing to which it refers. the indefinite pronouns anyone, anybody, everyone, everybody, someone, somebody, no one, and nobody are always singular.