A:Ca2+、NO3ˉ、CO32-、Na+
B:Na+、Ba2+、Mg2+、HCO3ˉ
C:NO3ˉ、Cu2+、K+、Clˉ
D:NO3ˉ、K+、AlO2ˉ、OHˉ
—Did you have fun _____________ on your last day off?
—No, I didn't. there were too many people and it was really crowded.
如图,已知斜坡AB的水平宽度是8米,斜坡AB的坡度为1:2,则斜坡AB的长为( )
—Sorry. We don't permit __________ in the lab.