除去下列物质中含有的杂质所选用试剂或操作方法不正确的一组是( )
物 质
所含杂质
除去杂质的试剂或方法
A
NaCl溶液
Na2CO3
过量盐酸,加热
B
CuO
Cu
灼烧
C
KCl
KClO3
MnO2,加热
D
O2
H2O
浓硫酸,干燥
A:A
B:B
C:C
D:D
I’m Nancy. I’m in Year 8 at Woodland School near London. It is a mixed school. Among all my subjects, I like French best ____.
Our school has a Reading Week every year. During the week, we can ____. We can ____. I often ____. Near the end of the week, we ____. Time ____.
已知函数f(x)=log3x,(x>0)(12)x,(x≤0),则 f(f(127))=( )