5. What does the pronoun “They” in paragraph 5 refer to?
a. UV radiation b. levels of the enzyme
c. Blaustein and Hays d. disappearing species
6. What kinds of amphibians are likely to become extinct?
a. Those with more enzymes which can repair DNA damage
b. Those with less photolyase
c. Those living in Oregon
d. Those receiving UV radiation
7. Which of the following is a “healthy” species of amphibian?
a. The western toad
b. The Cascades frog
c. The Pacific tree frog
d. The species native to Oregon