看图，选择合适的介词填空。

- Can I help you, Tim?

- Yes. I need a ruler. Give me a ruler, please.

- Where is it?

- It's____ the bag. Give me a pencil case, please.

- Where is it?

- It's____ the table. Give me a ball, please.

-Where is it?

- It's____ the table.

- Here you are.

- Thank you. Oh, where is my chair? I can't find it.

- Don't worry. It's here,____ the table.