trace+to+causes
131police — /peuh lees /, n., v., policed, policing. n. 1. Also called police force. an organized civil force for maintaining order, preventing and detecting crime, and enforcing the laws. 2. (used with a pl. v.) members of such a force: Several police are… …
132mass spectrometry — or mass spectroscopy Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. A mass spectrometer uses electrical means to detect the sorted ions, while a mass spectrograph …
