T cells and B cells differ in the form of the antigen they recognize, and this affects which antigens they can detect. B cells bind to antigen on invaders that are found in circulation outside the cells of the body, while T cells detect only invaders that have somehow entered the cells of the body.
ABS, DWV, Solid or Cell Core sewer pipe. The solid pipe is composed of ABS at 99% while the cell core is composed of a cellular foam between 2 layers of ABS which makes the cell core pipe lighter.
The Hub and Spigot are two types of fitting on either end of a pipe.At one end you have the Hub (Socket) fitting; which is a female end of a fitting designed to accept pipe or a SPIGOT connector.At the other end you have the Spigot fitting; which is a male end of a fitting designed to be used inside another fittings Socket (or Hub) end.