The boy is on the school football team,为什么用介词on?

the boy on the desk is Jake把on the the boy is sitting on a chair The boy is my brother who is on the bike. what is on () dask A,boy is .B,boy.C,the boy.D,the boy is .怎么填 The boy on the bike is my brother提问___ is the man on the bike? the boy is _(put)the apple on his finger. The boy on the tree is Tom改错 the boy ___(lie) on the beach is my brother There is a boy in the（ ） on the wall The boy (on the bike提问) is Mike. The dortor is busy_____(operate)on the wounded boy now. The boy is on the school football team 为什么on the team前要加is? the boy on the baicony is our monitor 对on the baicony提问 ------ ------- is ------monitor The boy is so tall that he can get the pears on the tree.The boy is tall ( )( )to The boy is in the bed .The boy is in the bed.这里为什么不用on 而用in The boy on the bike is my brother.(对 on the bike 提问） The boy on the bike is tom.对on the bike提问,快 The boy on the bike is my classmate.对on the bike提问