Professor: Members of most species are able to communicate with other members of the same species, but it is not true that all communication can be called "language. " The human communication system unquestionably qualifies as language. In fact, using language is a trait without which we would not be human. Student: I understand that communication by itself is not language, but how do you know that the highly evolved communication systems of songbirds, dolphins, honeybees, and apes, for example, are not languages? The student has interpreted the professor's remarks to mean that ['different species can have similar defining traits', 'every human trait except using language is shared by at least one other species', 'using language is a trait humans do not share with any other species', 'humans cannot communicate with members of other species']