— Nowadays, it seems that many young people can't live without smart phones.
— ________. I think it's bad for their health.
A:I'm afraid not
B:I hope not.
C:Exactly.
D:Of course.
在所有的两位数10~99(包括10与99)中,任取一个数,则这个数能被2或3整除的概率是( )
向NaCl、NaOH和Na2SO4三种溶液中,分别加入不同物质,通过一步反应都能生成化合物M,则M是( )