TOEFL Listening: ETS-TOEFL听力机经 - Y1005OWIOOU59YL5P$

What does the professor say about three-month-old infants? A. They have the ability to imitate vowel sounds. B. They can distinguish between vowels and consonants. C. They tend to cry with falling intonation. D. They tend to cry if they do not recognize a speaker's voice.