If you cannot positively identify a metal by visual identification, it should be _________.
Tested for unusual stress
Given magnet and spark testing
Treated as steel
Given ring testing
Corrosion presents a greater problem when it occurs in the vicinity of a/an _________.
School building housing wood-working equipment
Manufacturing plant with 100 automotive vehicles
Electrified coal mine
Office building lighted by fluorescent lighting
A pipeline is buried in cinders, corrosion will occur when the current _________.
Accumulates on the pipe's interior
Leaves the pipe
Enters the pipe