The Iran nuclear deal: full text - CNN.com
This comprehensive solution would build on these initial measures and result in a final step for a period to be agreed upon and the resolution of concerns.
I am wondering about to what the preposition upon is refer.
And, I think the verb result has two objectives, namely, the resolution and a step. Am I right?
Or, I am too confused about the following! I do not know its objectives and can not rephrase it
\\
result in a final step for a period to be agreed upon and the resolution of concerns.
Moreover, would anybody readily tell me the reason why there has been applied the tense future in past? and why have the previous sentences been used simple future?
Furthermore, Would somebody please tell me if we can write especially the last part of my original sentence, using the following?
Of which
Eventually, Could anyone please elaborate whether or not I have grammatically and properly written my question(interrogative sentences)?
Thanks in advance