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.

①我国居民的消费结构正在发生变化    ②我国人民的消费水平在提高

③人们的消费结构正在向享受型转变    ④人们正在攀比消费

某实验小组做“探究弹力和弹簧伸长量的关系”的实验．实验时，先把弹簧平放在桌面上，用刻度尺测出弹簧的原长L₀=15.50cm，再把弹簧竖直悬挂起来，在下端挂50g的钩码，每增加一个钩码均记下对应的弹簧的长度x，数据记录如表所示．