When it is time for bed, Sarah tosses and turns and stares at her clock for hours. She has a lot of difficulty falling asleep each night. What is MOST likely happening to Sarah? She is having night terrors. She has insomnia. She is sleepwalking. She is addicted to sleeping pills.

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.