下图是收集某气体的装置.由实验装置推测该气体的有关性质可能正确的是( )
A
B
C
D
密度比空气
大
小
溶于水中所得溶液的pH
>7
<7
A:A
B:B
C:C
D:D
This is the first time that your parents have been abroad, ______?
若二次函数y=(x-m)2-1,当x<1时,y随x的增大而减小,则m的取值范围是____.
I don't like swim.