21. Much to the disappointment of the neighboring countries, the Japanese government refuses to admit _______ crime they did in _______ World War II.

       A. the; the                          B. /; the                C. /; /                                 D. the; /

22. If _______ to a high temperature, water will change to vapour.

       A. being heated                    B. having heated           C. heated                      D. heat

23. Bob had thought his computer was broken _______ his little brother pointed out that he had forgotten to turn it on.

       A. if                                   B. before               C. after                               D. because