Thank you for your prompt reply!
I have to admit I still have a bit of confusion.
And Isaias since you say in your profile you can read French, I hope you won't mind my quoting a French sentence here which I think might be a similar case to the above sentence:
Il faut que nous alluminions le feu et que l'air contienne assez d'oxygène pour que cette énergie se dégage.
I extract this sentence from a French textbook and the author says the second que is a ellipsis of 'il faut que...'.
So I wonder why the sentence 'It is ... that ...., and that ...' is not another instance of ellipsis?