--where is class ---?--lt is on the --- floora\ six; thirdb\ sixth;thirdc\ six; threed\ sixth; three说理由!

--where is class ---?--lt is on the --- floora\ six; thirdb\ sixth;thirdc\ six; threed\ sixth; three说理由!
--where is class ---?--lt is on the --- floor
a\ six; third
b\ sixth;third
c\ six; three
d\ sixth; three
说理由!

--where is class ---?--lt is on the --- floora\ six; thirdb\ sixth;thirdc\ six; threed\ sixth; three说理由!
a,class one grade two表示二年级一班；third floor表示第三层,从第一层积累上去,first,second,third.表示第一,第二,第三