第33题: [单项选择]It was the first time that Mary was late. She ______ up in the traffic. A. could be held B. can have been held C. might have been held D. might be held 参考答案:C 答案解析:[分析] 表示对过去发生事情的猜测,用must have done或might have done。前者把握性更大些。
第34题: [单项选择]下列操作中,不能退出Excel的操作是()。 A. 执行"文件→关闭"菜单命令 B. 执行"文件→退出"菜单命令 C. 单击标题栏左端Excel窗口的控制菜单按钮,选择"关闭"命令 D. 按快捷键[Alt]+[F4] 参考答案:A