第3题: [单项选择]CIDR地址块192.168.10.0/20所包含的IP地址范围是______。 A. 192.168.10.0~192.168.12.255 B. 192.168.10.0~192.168.13.255 C. 192.168.10.0~192.168.14.255 D. 192.168.10.0~192.168.15.255 参考答案:D 答案解析:[解析] CIDR地址由网络前缀和主机号两部分构成。CIDR将网络前缀都相同的连续的IP地址组成“CIDR地址块”。本试题中,网络前缀的长度为20位,主机号为12位,因此192.168.10.0/20
第29题: [简答题]By the time the youngest was fifteen, the mother would have been in her early fif-ties and would expect to live a further twenty years, during which chance and health made it unusual for her to get paid work. 参考答案: 答案解析:到最小的孩子15岁时,母亲就已经50岁出头,虽然还能再生活20年,但此时的机会和健康状况使得她们很难找到有报酬的工作。