What are the benefits from achieving an optimal level of fitness?

Energy needs, in total kilocalories per day, are greater during than any other time of life. a.childhood b.infancy c.adulthood d.adolescence

Which of these are fast-acting compounds that attack ocygen-dependent tissues known to be particularly sensitive to these compounds? a.nerveb.vesicantsc.cyanide compoundsd.pulmonary

Why do rna viruses appear to have higher rates of mutation? a) rna nucleotides are more unstable than dna nucleotides.b) replication of their genomes does not involve proofreading.c) rna viruses can incorporate a variety of nonstandard bases.d) rna viruses are more sensitive to mutagens.