TRICK 1.--A is almost strong enough to lead the trump originally, but
holding the ace and king of a suit his best play is to take a view of
the dummy hand.
TRICK 2.--The queen of spades falling in the dealer’s hand indicates
that the weak hand will ruff. A leads trumps through the strong hand.
TRICK 3.--B has no reason to wait for the trumps to be led through
again, as he does not hold a tenace over dummy. He, therefore, leads
the ace and then a low trump in order to exhaust trumps from the weak
hand.