第3题: [单项选择]______ three times in a row, the boxer decided to give up fighting. A. Because having been defeated B. Because being defeated C. Having been defeated D. Having defeated 参考答案:C 答案解析:分词短语在句中做原因状语,并且动作发生在谓语动词decided这一动作之前,因此需用完成时态,根据句意,拳击手是连续三次被击败,故需用被动结构,选项C正确。
第18题: [单项选择]SQL语言集数据定义、数据查询、数据操纵和数据控制功能于一体,语句UPDATE实现( )功能 A. 数据定义 B. 数据查询 C. 数据操纵 D. 数据控制 参考答案:C 答案解析:[解析] SQL语言集数据定义、数据查询和数据操纵和数据控制功能于一体。数据定义语言的动作包括CREATE、DROP和ALTER;数据操纵语言的动作包括:INSERT、UPDATE和DELETE;数据