A:can you
B:you ca
C:would you
D:you would
X
Y
Z
①
Cu
CuO
Cu(OH)2
②
CH3CH2OH
CH3CHO
CH2═CH2
③
Na2CO3
NaOH
NaHCO3
④
CaCO3
CaO
Ca(OH)2
下列做法有利于保护生态环境的是( )
中耳的组成( )