A:滴加石蕊试液显红色的溶液 Fe3+、NH4+、Cl-、SCN-
C:水电离出来的c(H+)=10-13mol/L的溶液 K+、HCO3-、Br-、Ba2+
B:pH值为1的溶液 Cu2+、Na+、Mg2+、NO3-
D:所含溶质为Na2SO4的溶液K+、CO32-、NO3-、Al3+
We need two students____ (clean)the classroom.
They need help at the old ____ (people)home
Do you make any ____ (friend)here?
Mr.Wang teaches ____(they)math.
Sally is busy ____ (do)her homework.
小明和三名女生、四名男生一起玩丢手帕游戏,小明随意将手帕丢在一名同学的后面,那么这名同学是女生的概率为( )