用适当的介词填空

（1）The Hope Project has built many schools big classrooms and libraries.

（2）Paris is the largest cities in the world.

（3）I regard you my best friend.

（4）No one can be successful hard work.

（5）Did you see an old tree across the old house?

（6）We can't pass the exam we study hard.

（7）Could you tell me something interesting the old man?

（8）The young girl has been to ten countries five years ago.