According to observations conducted by biologist Dr. John _______ crows are capable of using tools to extract insects from tree bark.
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writingWhich choice completes the text so that it conforms to the conventions of Standard English?
A
Marzluff, an expert in avian intelligence,
B
Marzluff, an expert in avian intelligence
C
Marzluff an expert in avian intelligence
D
Marzluff, an expert in avian intelligence
Correct Answer: A
Choice A is the best answer. "An expert in avian intelligence" is a nonrestrictive appositive describing Dr. John Marzluff. It must be surrounded by commas.
Choice B is incorrect because it is missing the closing comma. Choice C is incorrect because it lacks punctuation for the appositive.