When someone had been exposed to valeric acid, for example, he tended to react negatively to a face.
比如某人闻到缬草酸时，他对看到的脸就会有不好的反应。
2
In the case of valeric acid, for example, that concentration was seven parts per trillion-a level only just detectable by bloodhounds.
比如，缬草酸的汗臭味浓度为万亿分之七，这种浓度只有警犬才能发觉。
3
If propionic, butytric, iso-valeric, hexanic acid et al short-chain fatty acids were detected in urine of human, the urine can be regarded as pathologic urine.