What is the most common illegal drug in the united states?

So i have a lot of answers answered but it says i still need to answer more questions. why is it doing that? how many questions need to be answered?

Viruses use the host's machinery to make copies of themselves. however, some human viruses require a type of replication that humans do not normally have. for example, humans normally do not have the ability to convert rna into dna. how can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires? a) the virus causes mutations in the human cells, resulting in the formation of new enzymes that are capable of performing these roles. b) the viral genome codes for specialized enzymes not in the host. c) the virus infects only those cells and species that can perform all the replication roles necessary. d) viruses can stay in a quiescent state until the host cell evolves this ability.

Effective antiviral drugs are usually associated with which of the following properties? a) interference with viral replicationb) prevention of the host from becoming infectedc) removal of viral proteinsd) removal of viral mrnas