防火墙的基本工作原理是对流经它的IP数据报进行扫描,检查其IP地址和端口号,确保进入子网和流出子网的信息的合法性。
参考答案:对
汉译英:“承兑交单;付款交单;货到即付”,正确的翻译为:( )
A. document against acceptance; document against payment; payment against arrivalB. document against payment; document against acceptance; payment against arrivalC. document against acceptance; payment against arrival; document against paymentD. payment against arrival; document against payment; document against acceptance
有以下程序: main() int a,b,d=25; a=d/10%9;b=a&&(-1); printf("%d,%d\n",a,b); 程序运行后的输出结果是______。
A.6,1
B.2,1
C.6,0
D.2,0