Studies of ----- among ocean quahogs are sometimes ----- by the fact that the subjects live so long that researchers die before the studies can be concluded.
A
B
C
D
E
The correct answer is .
The difficulty level is .
of students answered this question correctly.
Since the sentence talks about how the studies cannot be concluded because the quahogs outlive the researchers, the first blank needs a word that talks about ocean quahogs’ long life or B (longevity) and the second blank needs a word that means hinder or impede B (hampered). The answer is (B) longevity ... hampered.