除去下列不纯物质中的少量杂质(括号内为杂质),请填入适当的试剂
(1)Cu(Al)____ (2)Fe2O3(Al2O3) ____
(3)NO(NO2) ____ (4)NaCl溶液(Na2CO3) ____.
转动下面的转盘,下面说法正确的是( )
____ wasn't quite clear.
2.1×0.3=
0.5×0.8=
3÷0.5=
2.1÷0.3=
0.37÷0.1=
0.25×4=
3.6÷6=
4×0.23=
3÷2=
0.64÷0.8=