A:SO2和SiO2
B:NaCl和HCl
C:CCl4和KCl
D:CO2和H2O
某日晨7时36分,北京天安门广场举行了隆重的升旗仪式(日出时举行).据此回答下题.
—What's the _______ of those books?
—Two yuan each.