Which exercises in this activity might present challenges for a smoker but not a nonsmoker? Why would such exercises be challenging for them?

Brainliest what are fingernails made of?

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.

Jessica is a friend dislodge a piece of meat from her throat. she delivers five blows on her friend’s back with her fist and then gives him five abdominal thrusts. is jessica doing the procedure correctly? 1 no, she should use the heel of her hand for the blows. 2 no, she should use the side of her hand for the blows. 3 no, she should use her elbows to deliver the blows. 4 no, she should use a tennis ball to deliver the blows.