Первые четыре буквы, пожалуйста. Спасибо

1.CH4+Cl2=CH3Cl+HCl
CH3Cl+NaOHв=NaCl+CH3OH
CH3OH+CuO=Cu+H2O+HCOH
HCOH+Ag2O+NH3=Ag+HCOOH
2.CO+H2=CH3OH
CH3OH+CuO=HCOH+Cu+H2O
HCOH+Ag2O+NH3=Ag+HCOOH
3.C2H2+H2=C2H4
C2H4+HOH=C2H5OH
C2H5OH=H2+CH3COH
CH3COH+Ag2O+NH3=Ag+CH3COOH
4.CH4+O2=C2H2+2H2O
C2H2+HOH+CH3COH
CH3COH+H2=C2H5OH