一定会有新物质产生的变化是( )
A:食物变质
B:烧碱潮解
C:矿石粉碎
D:分离液态空气
85-26+37=
设函数fx=2a-1x+b是R上的减函数,则有( )
I think July is ____ (hot) than any other month in our country. It's ____ (hot) month of the year.