http://grammar.ccc.commnet.edu/GRAMMAR/grammarlogs4/grammarlogs505.htm
Q:
....
Example: This is the story and truth of the entire situation, that you may know why I have done the things I have done thus far.
....
A:
"Story" and "truth" would be twin branches after the linking verb, the dual predicate. The "that clause" that follows (which contains two modifying clauses unto itself, "why I have done the things" and "I have done thus far") seems to be an appositive for the double predicate. (In fact, "story and truth" can probably be put on one line, as a singular entity, sort of like "macaroni and cheese.")
遠東時事精選II:
On Flores Island, for example, skeletons have been found that prove the existience of rats as big as dogs, and elephants as small as ponies.
http://alt-usage-english.org/excerpts/fxthatvs.html
... when the relative pronoun is separated from the antecedent: "This is the only book in my personal library which I haven't read."
