下面这句话怎么样翻译，的意思是？谢谢。
When said in isolation, additional prosodic stress falls on the second word, but this disappears in the appropriate context.
这句话的前后文如下：
Stress patterns may distinguish a compound word from a noun phrase consisting of the same component words. For example, a black board, adjective plus noun, is any board that is black, and has equal stress on both elements.When said in isolation, additional prosodic stress falls on the second word, but this disappears in the appropriate context. The compound blackboard, on the other hand, though it may have started out historically as black board, now is stressed on only the first element, black.Some dictionaries mark secondary stress on the second element,, board. However, this is a typographic convention due to the lack of sufficient symbols to distinguish full from in unstressed syllables. See secondary stress for more. Thus a compound such as the White House normally has a falling intonation which a phrase such as a white house does not.A similar falling intonation occurs in phrases when these are emphatically contrasted, as in Not the black house, the white house!
When said in isolation, additional prosodic stress falls on the second word, but this disappears in the appropriate context.
这个句子中的when said in isolation是个悬垂修饰语。从上下文可以看出，said的逻辑主语不是句子的主语stress，而是the noun phrase 。因为这个句子依据上下文可以明确判断said的逻辑主语，因此这个悬垂修饰语不致于致使读者误解，因此便成了可以同意的。不过，最好还是不要省略从句的主语，将句子改为：
When the noun phrase is said in isolation, stress falls on the second word, but this disappears in the appropriate context.
翻译：a black board这个名词短语单独读出的时候，额外的步伐重音落在第二个单词上（即board）。但，在适合的上下文中，就没这种现象了。
