Don’t drink all your water ____
X
Y
Z
①
Cu
CuO
Cu(OH)2
②
CH3CH2OH
CH3CHO
CH2═CH2
③
Na2CO3
NaOH
NaHCO3
④
CaCO3
CaO
Ca(OH)2
提数学问题:____.
列加法算式:____.
列乘法算式:____.