单项选择
从A、B、C、D四个选项中，选出可填入空白处的最佳选项。
21.Xiao Hong worked harder last year. ，she still didn’t get high grades.
A. As a result B. After all C. By the way D. However
22. ---- What do you think made Mary so upset?
----__________ her new bicycle.
A. As she lost B. Lost C. Because of losing D. Losing
