A handheld toothbrush with a brush head having a forward free end and a rearward portion. When the crude acrylic acid containing the transition metal components as impurities is contacted with the cation exchange resin to remove the transition metal components therefrom, water is previously added to the crude acrylic acid prior to contacting the crude acrylic acid with the cation exchange resin. In a second aspect, the computer system comprises a plurality of servers, a management module for monitoring and managing the plurality of servers, a recovery mechanism coupled to the management module, and a bus coupling the recovery mechanism to each of the plurality of servers, wherein the recovery mechanism rebuilds a failed server onto another of the plurality of servers. Also provided by the invention are C. A membrane separates an outer space communicating with the pressure compensating bore from an inner space filled with a non-conductive fluid surrounding the female contacts. The personal clothing model can be used to identify additional images in which the person appears.