What has roots as nobody sees

What has roots that nobody sees, and is taller than trees. Up, up it goes, and yet it never grows. Check the answer here.

How much dirt is in a hole

How much dirt is there in a hole that measures two feet by three feet by four feet? Check the answer here.

If you look you cannot see me

If you look you cannot see me. If you see me you cannot see anything else. I can make anything you want happen, but later everything goes back to normal. What am I? Check the answer here.