Usage of a recycle bin and tree sapling

I met with a very weird old man...oops, I think weird Ah Gua is more suitable..>.< The reason I called him weird Ah Gua is he likes to ask silly question....

Here is the question that he/she questioned, and I bet you will find this funny too!!

Cao Ah Gua: Why you guys needs recycle bin n tree sapling and how you guys are going to used it?

We : *Speechless* *Silent* *Flies flew away*

You tell me, what should I reply him? Any idea???

Can anyone tells me that recycle bin any other usage except for used it to collect recyclable items? Can anyone tells me that tree sapling got any other usage except for plant it?

I really don't know..... Maybe Cao Ah Gua used recycle bin to keep his/her children, maybe Cao Ah Gua likes to eat tree sapling.....

I just don't know why Cao Ah Gua behave different from others.... haha...