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
(1)allergies to ozone
(2)mutations that lead to cancer
(3)viral diseases, such as AIDS
(4)ice formation at the poles