'be fully answered' is correct and usable in written English.
It usually follows a question that needs to be responded to completely. For example, "The project requires careful planning; can all these questions be fully answered?".
-- cannot be fully answered at this time.
It is a large question, and cannot be fully answered.
None of these questions can be fully answered before January 3rd, when the Democrats formally take control of Congress.
It is also possible to identify the areas that remain in dispute and the questions that have yet to be fully answered.
Whether he is, like De Gaulle, an authoritarian leader longing to restore the greatness of the state, has yet to be fully answered.
The reality is that even these and other basic questions cannot be fully answered, because not enough research has been done.
In the course of the novel, neither of these questions is fully answered, but gradually various implications appear.
But what's more striking than the theatrics is that the question — which should, indeed, be easy — still hadn't been fully answered.
There have always been two major critiques of Hayek's arguments, neither of which are fully answered by a rereading of "The Constitution of Liberty".
Among the questions that have not yet been fully answered are how seriously the White House, the Pentagon and the State Department took warnings they received last year from the International Committee of the Red Cross about mistreatment of prisoners in Iraq.
None of the questions Chomsky has posed has yet been fully answered, to his satisfaction or to anybody else's, but no scholar of the mind has ever been more influential.
