(CH3)3CHO\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CHO}(CH3)3CHO
CH3CHO\mathrm{CH}_{3} \mathrm{CHO}CH3CHO
CH3OH\mathrm{CH}_{3} \mathrm{OH}CH3OH
HCHO\mathrm{HCHO}HCHO