A:--What are you doing? --We are waiting for the bus.
B:--What are you doing? --We are waiting for the train.
截至今年一季度末,江苏省企业养老保险参保人数达850万,则参保人数用科学记数法表示为( )
在学校团体操表演中,男生有400人,女生有340人,每行站20人,女生比男生少站多少行?正确列式是( )