A.MgSO4 + NaNO3.
B.Ca(HCO3)2 + HCl.
C.Na2CO3 + H2SO4.
D.NaHSO4 + BaCl2.

A.Fe2O3, NO2, O2.
B.Fe, NO2, O2.
C.Fe2O3, N2O, O2.
D.FeO, NO2, O2.

A.C6H5CH2CH3.
B.C6H4-CH=CH2.
C.C6H5CH3.
D.CH3-C6H4-CH3.

A.butilen.
B.axetilen.
C.etilen.
D.propen.

A.Na2CO3.
B.KOH.
C.HCl.
D.H2S.

A.How to succeed in love every minute of your life.
B.How to turn failure into success.
C.How to make a millionaire.
D.How-to books.

A.advice
B.instruction
C.how-to books
D.career

A.
B.
C.
D.

A.
B.
C.
D.

A.
B.
C.
D.