——Where is Mr. Wang? ——He together with his students ________ Zhuyuwan Park.
A:has gone to
B:have gone to
C:has been to
D:have been to
如图,⊙O的半径为5,弦AB的长为8,M是弦AB上的动点,则线段OM长的最小值为( )
下列有关质量和密度的说法正确的是( )