twenty books are placed at random in shelf find the probablity that aparticular pairs of books shall be always together and never together​

What is the first step in trying to manage the stress in your life? a: recognize that you have too much stress b: identify acute sources of stress c: identify chronic sources of stress d: accept common life stressors which is a good strategy for managing stress? a: befriend happy people b: generate more income - (not it lol) c: review past challenges d: accept past failures

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.

Which of the following could use reverse transcriptase to transcribe its genome? a) ssrnab) dsrnac) ssdnad) dsdna