第15题: [单项选择]How much has the use of precision-guided weapons increased in the past few years A. Less than 6%. B. More than 6%. C. More than 3%. D. Less than 3%. 参考答案:C 答案解析:数字信息的找寻和判断。根据题干对数字信息的要求找到原文有关部分“…the proportion of such bombs used rose from no more than 3 percent
第21题:[单选题]设元素a、b、c、d依次进入一个初始为空的栈,则不可能通过合法的栈操作序列得到( )。 A.a b c d B.b a c d C.c a b d D.d c b a 参考答案:C 选项A:a进栈、a出栈、b进栈、b出栈、c进栈、c出栈、d进栈、d出栈
选项B:a进栈、b进栈、b出栈、a出栈、c进栈、c出栈、d进栈、d出栈
选项C:选项C无法实现
选项D:a进栈、b进栈、c进栈、d进栈、d出栈、c出栈、b出栈、a出栈