C-12-Q055mediumsingle_mcqইউরিয়ার সংকেত—aNH2-CO-NH2\mathrm{NH_2\text{-}CO\text{-}NH_2}NH2-CO-NH2bNH4Cl\mathrm{NH_4Cl}NH4ClcNH3\mathrm{NH_3}NH3dCO(NH2)2⋅H2O\mathrm{CO(NH_2)_2 \cdot H_2O}CO(NH2)2⋅H