从A、B、C、D四个选项中，选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。
21．Teaching ______ child to cook will improve many of the skills that he or she will need later in ______ life．
A．不填; the B．a; 不填 C．a; the D．the; a
22．His ability has never been in doubt --- the question is______ he is prepared to work hard．
A．that B．what C．since D．whether
