A:用浓硝酸和Cu制取NO2
B:用浓盐酸和MnO2制取Cl2
C:用H2O2溶液和MnO2制取O2
D:用NH4Cl溶液和Ca(OH)2制取NH3
一元二次方程x2﹣x﹣2=0的解是____
— No, _______two are still in the burning house.