GRE Text Completion: JiJing 1373-GRE填空机经1373题 - R3EEJ1OQVIT14U10A

Laughter, like speech, is primarily a human faculty, although both functions may also exist in a more ____________ form in lesser primates. A. indispensable B. crucial C. primitive D. intelligible E. recognizable F. rudimentary