Answer:
I occur twice in eternity. And I'm always within sight.
What is often returned, but never borrowed?
Other terms for this handy device include doohicky, doo-dad, and whatchyamacallit.
A blue man lives in the blue house. A red man lives in the red house. Who lives in the white house?
This is a plant named after a light source. What is it?
I will disappear every time you say my name.