What is the general relationship between exercise and the heart rate in humans

Enzo sits with a small group of friends at lunch. lately, he has been very quiet and stays home a lot even though his friends invite him to go places. he likes to play video games in his free time and is slightly overweight. which behavior is a sign that enzo may need professional mental health treatment? a) being overweight b) playing video games c) withdrawing from activities d) having a small group of friends

Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. how do physicians estimate the extent of burn damage associated with such dangerous fluid loss?

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.