The water cycle involves water in the liquid, solid, and gaseous states of matter. in which of the following earth systems can water be found in one or more of these states?
a.
atmosphere
b.
hydrosphere
c.
lithosphere
d.
all of these

The heart and lung are located in which cavity ? thoracic

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.

Which method of administration would result in the highest concentration of the drug in the brain?