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。
例:It is generally considered unwise to give a child __________ he or she wants.
      A.however            B.whatever         C.whichever       D.whenever
答案是B.
21.Don’t be afraid of asking for help __________ it is needed.
      A.unless               B.since              C.although         D.when
22.A cook will be immediately fired if he is found _______ in the kitchen.
      A.smoke               B.smoking         C.to smoke         D.smoked
23.Allen had to call a taxi because the box was _________to carry all the way home.
      A.much too heavy                                   B.too much heavy
      C.heavy too much                                   D.too heavy much