细胞分化是指( )
2HCOONa △__ Na2C2O4+H2↑ ①
2HCOONa △__ Na2CO3+H2↑+CO↑②
Na2C2O4 △__ Na2CO3+CO↑ ③
下列说法正确的是( )
句型转换。
How many spoons are there?