A graph titled Percentage of Teens with Dating Experience by Age Group shows ages on the horizontal axis and percentage of teens on the vertical axis. Of teens age 13 to 14, 11% have dated in the past, 15% are currently dating not seriously, and 20% are currently dating seriously. Of teens age 15 to 17, 19% have dated in the past, 25% are currently dating not seriously, and 44% are currently dating seriously. According to research, older teens are in serious relationships
younger teens.

Among 13–14-year-olds, about __%
are currently __% in relationships that are not serious.

__% of 15–17-year-olds have experience with dating compared to __%
of 13–14-year-olds.

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.