解析: 题干中已经明确指出答案出自第一段,因此根据题干关键词They don’t talk the same language可定位到最后一句“‘They don’t talk the same language’ has a major metaphorical meaning alongside its literal one”, 可知本题考查的应该是这句话的隐喻意思,因此应该在第一段中进行概括总结,这时会发现倒数第二句“‘Common language’ here usually means a foreign language, but the same point applies in principle to any encounter with unfamiliar dialects or styles within a single language”,意思是“共同语言指的是一门外语,但是说同一语言下的不熟悉的方言或文体内也会有类似的问题”,由此可知,这里They don’t talk the same language应该理解为在方言和文体上存在的问题。该句先是说通常情况下,所以该题选C。