A:27
B:﹣11
C:﹣6
D:3
黄种人主要分布在( )
When he came back, his _________ look on his face, he failed in the interview.
将O2、C、CO、CuO、NaHCO3、稀盐酸六种物质两两混合,有CO2生成的化学反应有( )
下列各句中,没有语病的一句是( )