【正确答案】
C
【答案解析】[听力原文] Long before they can actually speak, babies pay special attention to the speech they hear around them. Within the first month of their lives, babies' responses to the sound of the human voice will be different from their responses to other sorts of sounds. They will stop crying when they hear a person talking, but not if they hear a bell rings. At first, the sounds that an infant notices might be only those words that receive the heaviest emphasis and that often occur at the ends of sentences. By the time they are six or seven weeks old, babies can detect the difference between the rising and falling of tones. Very soon, these differences in adults' stress and tones can influence babies' emotional states and behavior. Long before they develop actual language comprehension, babies can sense when an adult is cheerful or angry, attempting to do or stop doing something, and so on, merely based on the rate, volume, and melody of adults' speech. Adults make it as easy as they can for babies to pick up a language by exaggerating such characteristics. One researcher observed babies and their mothers in six diverse cultures and found that, in all six languages, the mothers used simplified grammar, short sentences, and transformed certain sounds into baby talk. Other investigators have found that when mothers talk to babies who are only a few months old, they often raise their volume, and speak slowly. They also exaggerate their facial expressions, and emphasize certain words. More significant for language development than their response to general intonation is observation that tiny babies can make relatively fine distinctions between speech sounds. In other words, babies enter the world with the ability to make precisely those perceptual discriminations that are necessary if they are to acquire aural language. Babies obviously derive pleasure from sound input, too: at even as young as nine months they will listen to songs or stories, although the words themselves are beyond their understanding. For babies, language is a sensory-motor delight rather than the route to dull meaning that it often is for adults. What does the talk mainly discuss? 讲话开头便提出：“在真正会说话之前的很长时间里，婴儿会特别关注周围的话语。”接下来便具体阐述他们如何对人声产生反应，因此答案为C。A、B两项只是讲话内容的一部分，不能概括其主要内容；而D项中“对声音的反应”范围被扩大了，不符合文意，故排除。
【正确答案】
B
【答案解析】[听力原文] According to the talk, why do babies listen to songs and stories, even though they cannot understand them? 讲话者最后提到：“对婴儿来说，语言是一种感官运动的乐事，而不是通常对成人来说枯燥乏味的信息传递途径。”这里的“感官运动的乐事”，是指语言对婴儿来说是一种听觉上的享受，即他们喜欢这些声音，故选B。