A:CrO3 + NH3 + H2O
B:Cr2O3 + NH3 + H2O
C:CrO3 + N2 + H2O
D:Cr2O3 + N2+ H2O
At school, we are taught _______ knowledge _____how to behave well.
和平交往是人类社会交往的主流。下列不属于人类和平交往的是( )