帮我解决一些英语题,并讲明原因．谢谢!
1．Children should make()for old peoplein a bus.
A.room B.a room C.rooms D.thr room
2.Do you believe there are two( )in my class?
A.Maries B.Marys C.Mary's. D.Marys'
3. Can you find New York ( )this map of America?
A.in B.at C.of D.in