Hiv shows a high degree of variability because:
a. hiv is derived from many different strains of monkey viruses
b. hiv has been infecting humans for a long time
c. prolonged use of anti-hiv drugs results in resistance
d. the enzyme responsible for copying the genetic information of hiv from rna to dna is
error prone
e. all of above

In what way are cities microclimates?

Check all that apply diatoms are marine algae that have a shell made of silica, what are some of the uses of the silica shell after the diatoms die? 1.the shells make up the diatomaceous earth used in filters 2.it can be used as an ingredient in abrasives 3.they are used in food products 4.the shells can be used in some insulating materials

What is the importantence of the carbon and nitretan cycles in the environment