Biodegradable anionic polymers are disclosed which include recurring polymeric subunits preferably made up of dicarboxylic monomers such as maleic anhydride, itaconic anhydride or citraconic anhydride. The coding sequence of each nucleic acid species encodes a RNA cleavage substrate comprising a unique compomer species and a cleavage site. In a second aspect, a portion of the security block covers unused IO ports thereby preventing USB memory devices and other devices from being connected to unoccupied IO ports. At the time of adjusting a modulation factor, the control voltage Vtm to the control terminal for modulation of the VCO is controlled and also the input voltage Vtl is measured and a modulation sensitivity of a frequency of the VCO to Vtm is calculated and a modulation factor of the phase modulation data is adjusted based on the modulation sensitivity obtained. At least one speech recognition method and at least one language identification method are used on the digitized speech input in order, by logical evaluation of the results of the method, to identify the language of the speech input.