21.I wonder what it feels like to be one of _ ___ really rich. The Brows already have Rolls Royce and now they are buying _____ third.
A. the; the B.不填; a C. the; a D.不填; the
22.It is __ _____ he often fails in exams ________ makes his parents worried about him.
A. what; that B. that; what C. that; that D. /; that