第13题: [单项选择]In spite of what we said, be refused to ______ to the police station. A. give away B. give off C. give himself away D. give himself up 参考答案:D 答案解析:本句的意思是:不管我们说什么他都拒绝向警局首首。give sb. up意为“自首”,表示对……没有希望。例:It was so late that we had given him up,已经很晚了,
第14题: [单项选择]My friend and classmate Paul ______ horse-riding in his spare time. A. practice B. practices C. is practiced. D. is practicing 参考答案:B 答案解析:Paul既是我的朋友还是我的同学,主语指的是一个人,故谓语动词用单数,且根据题意,此处需用一般现在时态的主动语态。
第15题: [单项选择]下面IP地址属于B类IP地址的是( )。 A. 130.111.168.1 B. 128.108.111.2 C. 202.199.1.35 D. 294.125.13.110 参考答案:B 答案解析:死锁避免策略提高了资源利用率,但是增加了系统开销。