4. The problem of deciding at what point a baby’s imitations can be considered as speech________.
A. is important because words have different meanings for different people
B. is not especially important because the changeover takes place gradually
C. is one that should be properly understood because the meaning of words changes with age
D. is one that should be completely ignored(忽略)because children’s use of words is often meaningless
5. The speaker implies________.
A. parents can never hope to teach their children new sounds
B. children no longer imitate people after they begin to speak
C. children who are good at imitating learn new words more quickly
D. even after they have learnt to speak， children still enjoy imitating
答案解析：BDABD
1. 该问题的关键在Before start speaking，短文的第一段的第二句话明确给出“Children are greatly different in the amount of listening they do before they start speaking”。根据这句话答案选择B
2. 在这个问题中，需要注意的是“who start speaking late”，也就是第一段第二句话中提到的“later starters”。所以回答这个问题还需要在第二句话中寻找答案“later starters are often long listeners.” long listeners在指的就是often take a long time in learning to listen properly，所以答案选择D.
3.关键词回归定位，首先要找到“noises”在第二段，所以需要在这段内容中寻找答案。 在第二段第二句话 “during the first few months one or two noises sort themselves as particularly expressive as delight， pain， friendliness， and so on. ” 中 我们不难发现，delight， pain， friendliness这些词都是表达孩子的情绪和感觉(moods and feelings)，所以答案选择A.
4.在第三段中我们可以找出答案“it is clear that what a child means by a word will change as he gains more experience of the world .”这句话的意思是说“一个孩子通过一个单词要表达的意思会随着经验的增多而有所变化”，所以该题的答案选择B.
5.这道题可以用排除法，首先，通过最后一段的这句话“Playful and meaningless imitation of what other people say continues after the child has begun to speak for himself”，我们可以看出，孩子在长大以后会继续模仿大人的说话，所以排除B选项；C和D选项的内容在文章中没有提及。而A选项中提到了“teach their children new sounds”与最后一段中的最后一句话呼应，所以通过排除法选择A.