while having a discussion Technician A says that a multi-vis oil helps to combat engine wear because it flows more quickly to the bearings when the engine is first started. Technician B says that multi-vis oil actually accelerates engine wear. who is correct?

When cell phones were first entering the market, they were relatively large and reception was undependable. all cell phones were essentially the same. but as the technology developed, many competitors entered, introducing features unique to their phones. today, cell phones are only a small fraction of the size and weight of their predecessors. consumers can buy cell phones with color screens, cameras, internet access, daily planners, or voice activation (and any combination of these features). the history of the cell phone demonstrates what marketing trend?