At one point, scientists observed that the ozone shield was getting thinner. they warned that the loss of the effectiveness of this shield may lead to an increase in
(1)allergies to ozone
(2)mutations that lead to cancer
(3)viral diseases, such as aids
(4)ice formation at the poles

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

b. read the phase at the intersection of any given temperature and pressure.

69 is the correct math for the amino acids