They would be here for observation only, to gather knowledge , which is the only resource of value to such a civilization .
(They; would be; here; for observation only) (They; to gather; knowledge , which is the only resource of value to such a civilization) (knowledge; is; the only resource of value to such a civilization)
They They knowledge
would be to gather is
here for observation only
knowledge , which is the only resource of value to such a civilization
the only resource of value to such a civilization