If 你 have it, 你 want to share it. If 你 share it, 你 don't have it. What is it?
A secret.

The 更多 你 have of it, the less 你 see. What is it?
Darkness

What book was once owned 由 only the wealthy, but now everyone can have it?
You can't buy it in a bookstore 或者 take it from a library.
A telephone book.

What gets whiter the dirtier that it gets?
A chalkboard

What happened in the middle of the twentieth century that will not happen again for 4,000 years?
The 年 1961 can be read upside down and that won't happen again until 6009!

What has no beginning, end, 或者 middle?
A doughnut.

What has to be...