Aveto can occur when the president is presented a bill during the last ten days of a legislative session and be overridden by a two-thirds vote in both houses of congress.

The answer to the first unknown is "POCKET" while in the second unknown is "CANNOT". Hence, in order for us to complete the statement in the problem we have it, a POCKET veto can occur when the president has presented a bill during the last ten days of a legislative session and CANNOT be overridden by a two-thirds vote in both the house of Congress.

Of the revolutions of 1848.