There are significant physiological differences between reptiles and birds; for instance, the former rely on external heat sources, _________ the latter generate their own body heat.
2
writingWhich choice completes the text so that it conforms to the conventions of Standard English?
A
or
B
while
C
although
D
because
Correct Answer: B
Choice B is the best answer. The sentence contrasts reptiles with birds. "While" effectively signals this direct comparison.
Choice A is incorrect because "or" suggests a choice. Choice C is incorrect because "although" typically introduces a concession. Choice D is incorrect because "because" implies causation.