Anyway, the typical CEA range is < 3.0 ng/mL (that is < 30mg/DL). Some folks are naturally higher. Others are in that range. Sometimes certain cancers will elevate a patients CEA levels, othertimes or with other cancers, CEA will be normal. Sometimes other things elevate CEA. Typically, from what I've read, heard, and studied, most doctors would say CEA < 10ng/mL (< 100ug/DL) could be normal or caused by things like smoking, not really a cause for alarm, but screening might be in order to determine the cause.
Operating System. An operating system or OS is a software program that enables the computer hardware to communicate and operate with the computer software. Without a computer operating system, a computer and software programs would be useless. The picture is an example of Microsoft Windows XP, a popular operating system and what the box may look like if you were to visit a local retail store to purchase it.
An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.