题干
一Where are they from?
一Most of them from China. A small number of them from England.
A：is; is
B：Is; are
C：are; are
答案(点此获取答案解析）
C
一Where are they from?
一Most of them from China. A small number of them from England.
A：is; is
B：Is; are
C：are; are
的柱坐标为 
，则它的球坐标为( )
